He has to hide his homosexuality from the public sphere for fear of incarceration - Arenas does indeed end up in prison. Schnabel, in this regard, establishes artistry as the most admirable virtue. It is the vehicle of truth and its creators are heroes among men. Art is good. Art is life.
Art is, yeah, all that cool stuff.
Schnabel makes no pretenses about hiding his reverence for art in the film - that is, after all, the point of his film. He explores the way that oppressive structures can work diligently to silence the voices of artists, and while they may temporarily succeed, only art lasts forever. Moreover, Schanbel does not simply villainize Castro's oppressive communism. He does not depict Cuba as a suffocating environment that one must escape from in order to have artistic and sexual freedom. In fact, he does quite the opposite.