The "comedy" of that movie basically boils down to "look at me make huge exaggerated motions and talk in a silly voice".
Hard to watch nowadays due to the transphobia, but it was a simpler, more ignorant time.
I guess being trans myself, I don't find the transphobic bullshit so easy to overlook. Maybe if they hadn't been so extreme and over the top with it I could forgive it. Glob knows there are shows/movies I like that are a little transphobic. The idea of respect for trans people being even slightly mainstream is a fairly recent thing, after all. But I guess I can't really ignore it when the climax of a movie is several minutes of a room full of cops vomiting because they found out the woman they all had sex with or made out with or whatever it was has male genitals.
It's like saying you can't enjoy To Kill A Mockingbird because Bob Ewell's a racist.
Not at all. To Kill a Mockingbird had racist characters, but the plot of the book was about a black guy being facing unjust racist bullshit from the justice system and the white people of his community. The racism wasn't presented as good, it was presented as a force of evil to be overcome. Ace Ventura just had gratuitous transphobia that was presented as perfectly normal and not bad at all, and which even came from the film's titular hero. There was no counterpoint, just a "joke" that relied on bigotry to work.