It can be said that the problems with sexual violence in India are rooted in problems of how sexuality is perceived and how Indian society responds to sexuality in general . This is often problematic with the general perception of sexuality and any conversation or display of sexual behavior being considered taboo. There also exists several social behaviors within families, offices and other spaces that contribute to Indians having a problematic outlook on sexuality. This is often the lack of sensitization and sex education. It only adds to the problem that a vast majority of Indian schools do not have any form of sex education and attempts to introduce such curriculum has only led to staunch opposition from the public. This opposition too is rooted in Indian societies repressive views on the body and sexuality. There are numerous such problems that contribute to sexual violence in Indian. At the same time it has to be said the Indian union is a large country with an immense amount of diversity. Thus sexual behavior, perspectives and types of sexual violence differ vastly across communities and regions. There are even parts of India where sexual violence is minimal and the social taboos are different from the mainstream. For the sake of this summation the general features of Indian sexuality will be analyzed. The majority of the views on sexuality that is now present in mainstream Indian society is derived from the perspectives about gender and the body that took shape in the colonial period. It can be said that these perspectives are the consequence several Victorian values of sexual behavior being re articulated in the 19th century by Indians. The major changes that happened during colonialism is the changes to how the Indian family was organized. Now this change was not sudden. The changes in Indian sexual behavior changed slowly over the colonial period into post colonial India and was also influenced by socio-political movements during the nehruvian era. By the end of the 20th century the predominant form of family in India was a nuclear family with a patriarchal head. It was common within this family structure to inhibit sexual behavior. This also led to a social consensus on sexuality that would shame any expression of the body or sexuality. For a general summation it can be said that perspectives of sexuality that Indians derived from colonialism, certain social movements and nehruvian socialism have corrupted into the problematic views Indians hold today. These ideas are -sexuality limited to procreation, Patriarchal family units, body shaming for expression of sexuality and the segregation of the genders.

Now does this mean pre-colonial India is free of sexual violence? Absolutely not, but the current problems with Indian sexuality derive from how Indian sexual behavior was organized in modern times.

[EDIT] The perspectives that create problematic sexual behavior in contemporary India cannot be assigned to any one historical, political or social phenomenon. There are a variety of factors that play into how the Indian approach to sexuality is defined. The diversity of the subcontinent again is a impediment to providing a general causality to the problem of sexual violence. For the purpose of answering this question I'll delve into a few such social changes that occurred during the modernization of Indian society. This does not fully explain the problem but traces how certain kinds of perspectives on sexuality emerged and were re-articulated in India during the colonial and post colonial period. As colonial rule spread into the Indian subcontinent the British began to establish (initially in the presidencies) a modern state and an industrial economy. What came with this economic change was also new values of individual enterprise, nuclear family units, sexual modesty and other 19th century social perspectives. This was rooted in philosophies like the protestant ethic, which prioritized work over pleasure and sexuality as only a means of procreation. Sec 377 of the Indian penal code which was originally designed by colonial rule in 1861 is a good example to explain the impact of these value systems. Sec 377 criminalizes 'unnatural sexual behavior' which is defined as sexual behavior against 'the order of nature'. While the main focus of this law has in recent times shifted to the debates on its decriminalization of homosexuality the scope of the law goes further. Technically sec 377 deems any sexual act that is not for the purpose of procreation as illegal. The other law which also are indicative of the transition of Indian society's sexual values is sec 375 (which also has roots in English law) defines rape only as the crime of man against a woman. India also still does not have a law against marital rape. All of these laws and their problems are currently being debated in India's supreme court. Historically these laws which all derive from laws from the 19th century indicate the social change in the perspectives about sexuality. The 19th century also saw several reform movements that redefined how Indians understood the body, gender and sexuality. Several reformers like Raja Ramohun Roy and Ishwar Chandra Vidya Sagar actively used the colonial state as a means to make illegal several practices like widow burning, child marriage and educational inequality of the genders in the household. The writings of these reformers also created the modern Indian perspectives of sexuality which are a mix of Victorian values merged with certain indic ethics that made it into the colonial age.

Several of these values transitioned into the beliefs of Indian nationalism which among other things saw the modern family unit as a contributor to the nation and the economy. Several thought streams wwithin Indian nationalism, especially Gandhism considered sexuality as a distraction and carnal pleasure which needs to be repressed done away with. Sexual modesty thus became a part of Indian social behaviour. The social changes in the family became more rigid and transferred through to several social groups(nationalists and indians within the colonial state) into the 20th century and towards Indian independence. Post colonial India saw the expansion of these values to most of the country. By the End of the 20th century the nuclear family unit was the basic unit of the Indian economy. The problems that arose in this post colonial society especially towards the end of the 20th and the beginning of the 21st century are numerous. To answer the present question a few of these problems can be elucidated. The modern Indian family is generally averse to displays of sexuality. Indian society in general considers sexuality and the body as something to be hidden. The social transformations in the modern age also meant that the diverse sexual behaviors of south asia were turned into a more homogeneous monogamous patriarchal society. The same processes that facilitated the abandonment of unequal practices from pre-colonial times later in history contributed to the creation of new unequal spaces and inequalities. These new unequal spaces gave the space for misogynistic perspectives and sexual violence to become rampant in Indian society. The general repressive mentalities on sexuality that had built up over time did not help the situation either.

Now none of these things I have written about can account for the entirety of the problem or establish exact causality but this is the historical context to keep in mind when trying to understand India's problems with sexual violence. The current problems are a consequence of history and placing them within that history is where to start studying them.

Is this a recent development, or something that goes back a long time but wasn't really reported on until recently?

Its inconclusive as to if India has become more misogynist in the past two decades or if the rate of reporting against sexual violence has increased. But it is evident that sexual violence has become a serious issue and there are much more mechanisms in India now to counter it.

Recommended reading
Madhavi Menon:A History of Desire in India

Janaki Nair: A Question Of Silence The Sexual Economies Of Modern India

Charu Gupta - Sexuality, Obscenity, Community: Women, Muslims, and the Hindu Public in colonial India

For Info on how the modern Indian consumer and their familial behavior was created read : Douglas Haynes: Towards a History of Consumption in South Asia