You're lumping a few bad apples (apparently recruited from Reddit) in with "they". The users who found the bugs and provided patches were largely courteous considering the circumstances.
Steve Klabnik makes this point in his write-up, but I'm restating it here for clarity. You don't get to cherrypick who is part of your community or not when these situations arise.
Those "bad apples" are part of the Rust community, and the Rust community needs to take responsibility for them the same way any community needs to take responsibility for their bad apples even if it's just to denounce their behaviour.
Good thing that those who submitted the patches and PRs were polite; they're not the ones who caused this maintainer to quit though I'd wager...
