As far as the original post, this isn't that bad considering what happens in other games.
I remember during my Destiny days how often I saw people selling carries on Trials of Osiris (basically a different kind of top level pvp). Which was ridiculous as it's a 3v3 elimination mode. It takes some brass to both sell and buy those. I bet there were a lot of unhappy customers.
It's still bad, don't get me wrong. Just because it happens elsewhere doesn't make it good, but it's one of those things any game with any sort of multiplayer will have.
I understand where OP comes from as I tended to avoid making LFGs for most games I played (GW2 included), and it took a bit to get over that. Sometimes you have to create some runs to get some runs. My recent personal experience compromises of a small sample size but it went mostly well; only one group didn't actually read the LFG and we ran a story mode for no reason at all (I should have said something); and one group of rushers that I joined (would have helped if they had said they were speedrunning it on the LFG, cause it went poorly and I almost quit).
Raids, and any other similar type of end-game content, are better done with guilds. There's more transparency, and the run's goals and "vibe" are known ahead of time. If I ever get into doing GW2 raids (which I doubt I'll ever do cause I'm more interested in other parts of the game) it'll be with a guild. Too many egos getting together in time consuming, challenging content is always something that will create silly drama.
Just look at this thread.
Moral of the story: put yourself out there, maybe join a guild, have some patience, ignore bad actors, think about your endgame goals, and enjoy your time.
I don't know why raids are dead in GW2 (I've been away for close to a decade), but once I saw that Heart of Thorns was coming out and there seemed to be a focus on this newfangled "Living World" stuff, I pretty much believed raids were never going to be a big draw as in other mmos. GW2, to me, was always around pseudo dynamic open world content, pvp, and the exploration of a gorgeous "themepark" mmo world.