I see the problems in 90% of the session I attend as threefold.
First, as there are so many aids available these days, there is absolutely no excuse for not having instruments in tune.

Second, people who loudly take over a tune that someone else has started, usually speeding it up as they consider it is being played too slowly, may not have considered that the original player might be a beginner, perhaps playing in public for the first time, and may not be capable of playing faster. Instead of helping someone to get better, this might put them off for life.

Third, I might have spent weeks learning to play a piece where I have taken care to arrange the chord structure and phrasing in a particular way to enhance the tune or song in MY style only to have some clueless idiot who has never learned to LISTEN, promptly decide that they know better than I how it should be played or sung.
Yes, I am giving a performance, that is why I am there. Yes, there is a certain amount of ego involved as I try to do my best. However, I don't go on and on beyond my allocated time and, if I get to play again, I will make sure that I then play something everybody can join in with.
There is so much faffing about, nonchalant forgetting of words, playing out of tune and general lack of pride in performance of our traditional tunes and songs, it is no wonder any media treat us as a joke.
Don't get me wrong, I think there are a lot of wonderful performers out there in sessionland but the few bring the rest of us down.
I wonder how many contributors to this thread have now been infuriated by these comments and how many will do anything about it's content.