I’ve rarely noticed comments like “people like you” or “you people” leading to productive discussion, though I’d be delighted to see an exception.
I am not sure that negative comments always have to include a solution; it’s sometimes nice if they do, but if for example I’m told “I played for an hour and I felt like nothing happened” or even more bluntly, “nothing happened when I was playing”, it may sting but it still gives me information. I can choose what to do with that information whether that’s shrugging and moving on, considering whether I want to shift things, replaying it myself with that in mind, or letting it sit for a bit and returning to it later.
If I said “I’m intentionally doing a slow pace, I’m happy with it as it is” and then a bunch of people jumped in and started insulting me over it, that would be a problem. But - especially if an author is actively looking for ways of improving their WIP, I don’t see much problem with blunt feedback that isn’t insulting an author.
But then we do roll on back to definitions, where some may see a comment as insulting where another may see the same comment as bracingly honest feedback. In general in these discussions and in WIP threads I try to read things in good faith and give the benefit of the doubt where possible. Sometimes (rarely) that isn’t possible, and sometimes the feedback just isn’t actionable, such as asking an author to reshape their game into something entirely different.
But mostly I see a desire from players to want to help improve a WIP, and/or they’re enjoying playing and want to chat about it and the characters. I don’t think I’m naive in thinking that’s the majority - at least if I am, it’s a naivety I’ll cheerfully keep.