The main reason I don't go is because there are too many no talent people wailing and slamming an instrument. I can't take 35 verses in some foreign language like Gaelic. I'm a word person, and if I don't understand the lyrics, my eyes glaze over after two or three verses.
Then there's the smoke and noise. Then there are those assholes who come only to hear themselves, and yammer away while others are performing.
Finally, those insensitive twits who record you without prior permission. I sometimes do something I have written and not yet copyrighted, or, maybe even finished yet, so I don't want it recorded.