It's just kinda become the culture of the game. Vetting someone requires a level of criticality, often through third party sources, and both criticism and third party tools are heavily demonized by a sizable chunk of the playerbase. There was a 50 some page thread not long ago about how evil criticism and having basic standards is.
In doing highend content these days, you'll often come across people that are willing to whiteknight on behalf of players who've knowingly joined a party well beyond their capabilities. I've been helping in countless instances of clear parties for the recent EX trials in which fresh people join, and the party lead just refuses to remove them. I was even called toxic and kicked from one for saying, word for word, "Why are we explaining the first phase in a clear party?" after someone admitted they had joined a clear party blind. Many people these days seem more concerned with maintaining a moral facade than with the value their own time and the time of others. Enabling bad players at your own expense is seen as an easy moral victory for some reason.
I donate a lot of my time to teaching others fights, and help with clear parties. It's something I genuinely enjoy doing. I've made most of my best friends through jumping into discord to do callouts and give explanations for peoples practice/clear runs of EX and Savage. You'll find this is never enough for some people. I still get lectured here and elsewhere, by people who've never really helped anyone, about my moral responsibility to players who have absolutely no respect for my time. I kind of just assume said people are guilty of the selfsame behavior, and in whiteknighting others are just kind of defending themselves by proxy.
But these are basically just anecdotes from my time on Primal/Crystal. It's possible it doesn't really apply as much to a more raid-focused datacenter like Aether.