I agree with everything you said except the bit about quality of life being similar. Don't those drugs have major side effects? Even if they don't, sex with another person is pretty much over at that point. Even if the other person has AIDS too there is a risk of reinfection.
Granted, having a similar life expectancy is nothing to sneeze at.
Actually, if you're on HIV suppressants, the virus levels in your blood is so low that it's almost impossible to infect other people through sex, even if you have unprotected sex.
The risk isn't 0%, but it's less risky to have unprotected sex with someone infected, but on suppressants, than to have unprotected sex with someone who doesn't know if he or she is infected.
Granted, having a similar life expectancy is nothing to sneeze at.