Both the Wikipedia page and the largest post on this subreddit seem to reflect the contested history surrounding the topic.
Common charges against Reagan is that he delayed in recognizing the disease, failed to fund research, failed to speak out on behalf of the ill, and actively prevented others from addressing the disease, and that his actions or lack of action were driven by a disregard or dislike of homosexuals.
There is a short and a long answer to this question. The short answer is yes, the "charges" against Reagan are, for all intents and purposes, correct. The long answer is yes, but it's complicated.
To expand a little bit on the long answer, it is helpful to think about what, precisely, we are asking when we examine Reagan's potential culpability. There are two questions here, one about actions and one about optics: "what did Reagan actually do (or not do) in regards to AIDS?" and "did he care (or was he perceived to care) about people with AIDS?"
Looking at the first question, it is pretty clear that Reagan was slow to respond to AIDS, and that the responses (in regards to funding and awareness) were significantly lacking. I want to be clear that even the President of the United States has a finite amount of power and agency, and so to blame the entirety of the AIDS crisis on Reagan would be unfair. That being said, Reagan as president set the tone for the response to the growing threat of AIDS. That tone ended up being "eh, not my problem." There were concrete steps he could have taken (more funding, more awareness) in the early years that would have saved or improved lives.
As to the other side of the question, it is very important to acknowledge how vital the president's role is in legitimizing crises. When the president talks publicly about a thing, it becomes A Thing. It was years (and thousands of dead) before Reagan acknowledged AIDS as A Thing that existed. Before that? Radio Silence. Reagan's personal views about gay people is far less important than how he publicly responded to an incidence of gay people in trouble. For the gay community, and for people with AIDS (gay or otherwise) Reagan's silence was proof that they were quite alone. That, just as much (and possibly even more) than the lack of concrete action contributed to the perception of Reagan's culpability in the AIDS crisis.
Paging /u/cephalopodie, She specialises in American LGBTQ history & The AIDS Crisis, so hopefully she can answer your question as it's fascinating :)