You can argue that that culture was very vulnerable to a disease like AIDS, and that's fair. You can argue that, had that culture changed faster and more comprehensively, it may have mitigated the crisis somewhat, and that's fair too - although I'd argue the effect would likely not have been very significant.
But to cast blame on the same communities which were repeatedly decimated in large part as a result of those authorities' lack of concern over whether they so much as lived or died - a lack of concern which, as Shilts' own work which you cite makes clear, was so persistent and profound as not to be shifted until gay people themselves fought their way into positions of sufficient power as to have meaningful impact on policy, and not until one of Ronald Reagan's personal friends died of the disease and thus forced him finally to recognize the essential humanity of others likewise afflicted? The kindest thing I can find to call such a position is insultingly absurd.