It was partially to transform the identity of Turkey towards a European-western version of itself. This isn't the entire reason for it, but one of the benefits for the change was to distance the population from the Ottoman legacy. By only being able to read latin alphabet texts, future generations would be unable to read the historical and cultural Ottoman texts (most of which were not translated), effectively giving Turkey a clean cultural slate. Edit: This facilitated the westernization process that was an important part of Ataturk's vision for the country. /edit

More importantly, this also had a strong impact on secularizing the country, something that Ataturk was very interested in. Islamic texts are mostly written only in arabic (I know there is a reason for this, but I can't remember why), and by changing the alphabet taught in schools, these texts would become unreadable (by default) to the majority of the population.

There was definitely some resistance among academics, who were opposed to the effective loss of literature, which largely became unavailable due to the language reforms. Many (Most?) ottoman era books were locked away in repositories during the transition, and were inaccessible to the public.

I would assume that there was also resistance from the religious sectors (Pissed that people couldn't read the Qur'an) but I don't have a source offhand for this particular claim so please treat it as educated speculation. I only bring it up because it is in my opinion a good starting place if you wanted to look further.

Ismael, T. Y. (2011). Government and politics of the contemporary Middle East: continuity and change. London: Routledge.