They’re allowed to complain, but that doesn’t make them correct. I don’t believe it to be wrong, because to a large extent people have a right to know public figures - they lack a right to privacy and must fight for every bit they want.
If I, say, found a coworker’s cringy Reddit account and shared it with other coworkers in a mean-spirited way, that would be rude and a transgression of privacy. If I found out that my state Senator, or my favorite YouTuber, had a private Reddit account and shared it, that would be okay (or even good, an act of transparency).
And there are of course levels to everything. Take the YouTuber example. We would obviously consider it more appropriate to share if the Reddit account showed they were bigoted or fraudulent somehow; or if it was boring and not notable. Less so if it contained highly vulnerable, personal stories, or (and pardon me if this is a bush you were beating around in your post) nude photos or videos.