While the play was conceived as AIDS was ravaging gay America, most gay men at the time did not have AIDS. However, it was true that the NYC theater community was decimated by the disease.
In choosing to have a character in the play who was a real life person, Kushner kept with reality in having Roy die of AIDS. He was also a “type”: homophobic, anti the notion of a gay identity,, closeted (but obvious), etc. There is always the dramatic satisfaction of seeing the mighty fall, or at least those who think themselves as the mighty. I remember one of the bitchiest insults from that time: “just get AIDS and die!” So at the time, and even now, there is a visceral schadenfreude that many can tap into when they see Roy suffer and die.
I think the Kushner tapped into something very much in the air by the time Perestroika was playing: triple therapy and medication cocktails not only halting the progression toward death but also restoring quality of life . Studies of NRTIs and protease inhibitors in combination to reduce viral load and minimize resistance were coming out in 1995, and by the end of the decade, most people still alive with HIV were on a cocktail. With NNRTIs and then more classes of meds, HIV is now viewed as a chronic disease.
The great work was about to happen, and indeed it was happening as many were in studies at the time.
Re. more characters in the play with AIDS. Louis, Joe, Harper, and Belize could have been infected. It’s possible. It’s also just as possible that they might not have been. And having more illness tales in a cast of 8 main people might have turned it into even more of an AIDS play than it already was.