OP's question is a little ambiguous, but I'm assuming that they're asking why the Philippines retained its name despite its colonial roots. 'The Philippines' or its quainter apellation 'the Philippine Islands' are Anglicized versions of Las Islas de Filipinas. Felipe or Philip of course was then-crown prince of Spain, known later as king who'd earn Spanish-Armada-fame. Initially, Las Islas Filipinas was first given to the islands of Samar and Leyte in 1543. As the Spaniards consolidated territories and carved new boundaries, Filipinas came to encompass all of these but especially the core island groups of Luzon, Visayas, and Mindanao - the same component parts as modern day Philippines.

The issue for detractors is that retaining Filipinas / Philippines / Pilipinas (Fil.) is a nod to a foreign monarch and to shameful colonial past. Additionally, some communities were never or barely controlled such as the Muslims of Mindanao. The solution, say critics, was and is a national rebranding. Suggestions have come and gone: Solimania, Luzvimin, Perlas ng Silangan, The Rizalinas, Malaya, and Haring Bayan Katagalugan were proposed as early as the Philippine Revolution. None of the alternatives have gained traction with the public.

The closest attempt at a name change coincided with the regime of the dictator Ferdinand Marcos. In the 1970s, Marcos embarked on a massive campaign coined the Kilusang Bagong Lipunan or New Society Movement. Meant to lend a star quality to his authoritarian rule, KBL propaganda included bequeathing the precolonial word Maharlika to an assortment of buildings, roads, organizations, and housing projects. Incidentally (or not) Marcos also claimed that Maharlika was his codename during World War II.

Broken down, Maharlika is a loanword from Sanskrit maharddhika - to be "of great power, wealth, or majesty". In prehispanic Tagalog society, maharlika was the status denoting a freeman. Cognates like Malay merdeka and Indonesian/Dutch mardjiker have to do with freedom or the idea of being released from bondage. Marcos imbued maharlika with a loftier image, erroneously thinking it meant royalty and nobility. Accurate or not, his intent was to call to mind an imagined precolonial greatness of which he as an enlightened autocrat was resurrecting.

In 1978, former Senator Eduardo Ilarde filed Parliamentary Bill 195 proposing it was high time for the country to reinvent itself. Whereas the The Philippines "merely reflects the victories of our invaders", Maharlika was "reflective of our customs, ideals, and traditions". Had it passed congress, a national referendum would have taken place. The bill was a stillbirth.

But even after Marcos' fall from grace in 1986, Maharlika as a possible national name could not be divorced from the Marcosian cult of personality. In 2019, President Rodrigo Duterte, known for his warm ties to the Marcoses, once again proposed the name change. His spokesperson quickly explained it away as the president simply "expressing an idea".

Sources:

Carta Hydrographica y Chorographica de las Yslas Filipinas - Fr. Pedro Murillo Velard et al.

"Filipinos To Be Called Rizalines" - Quennie Ann Palafox

"Vibora's Rizaline Constitution" - Chris Antonette Piedad-Pugay

Haring Bayan: Democracy and People Power in the Philippines - Michael Charleston Chua

"Duterte wants Philippines renamed 'Maharlika'" - Mikhail Flores, Nikkei Asia

"Hstory In Words" - Ambeth Ocampo, Philippine Daily Inquirer

Imagined Communities: Reflections on the Origin and Spread of Nationalism - Benedict Anderson

Edifice Complex: Power, Myth and Marcos State Architecture - Gerard Lico