Medicine not being able to fix things is part of the problem; maybe the exuberant optimism, the "technology will solve all our problems" attitude of a few decades ago has left people disappointed. Hard to imagine how science could have measured up against the expectations it gave people in the "western world" really.
Except that "science" did not give people any such expectations. People who sensationalized the capabilities of scientific research gave each other those expectations. Some of them were, unfortunately, scientists who overreached themselves, or were speaking about fields other than their own; but the majority were people, particularly journalists, who were just as ignorant of science and the scientific process as it's detractors are today.
But there's something else - "scientific medicine cannot cure AIDS... etc..." and it's at that point that often contact is lost and the "well, where do I go from here" question is too often left unanswered by a system concerned more with patients it can fix than with those beyond "cure" but still in need of support. There's a need there that isn't being answered.
Erm, yes, the "where do we go from here?" question
is being, and repeatedly has been, answered. It's just that the answers are not what they want to hear.
The answers that the scientific medical community can give right now are:
"We can't cure it yet; but we do have treatments available right now which are capable of relieving a considerable amount of suffering, and extending lifespan for a signifcant duration beyond what it would normally be without treatment, at a certain cost and risk."
And...
"We're continuing to research the problem. These are the difficulties we are facing, this is the progress that we've made so far, and these are the projections we can reasonably make based on the information we currently have."
But since neither of those answers is "We can definitely cure AIDS by this date, if not immediately, and entirely for free!" many people will not be satisfied with what the scientific medical community can tell them.
Contact is lost because too many people do not want to accept that reality. Some people will simply and flatly refuse to accept any answer that is not what they wish to hear; and in desperation will turn to anything that gives them more hope, which claims to give them the answer they do want, however false and clearly unworkable it may be.