I've never seen an actual good competitive player shit on a youtuber lol. Everytime I've seen someone be like "(name-drop youtuber here)? that dude sucks lol" they're not even low-mid open or silver highlander, it's literally ugc steel level and below players trying to act cool by pretending they're so high and mighty and above players that the more mainstream tf2 population would know. Unfortunate that they're associated with competitive as a whole, especially when they're more or less glorified pubstars.
even then it's usually people doing that to people like stabby or uncle dane, people with really defined "mains". Never really saw it much with star.
edit:
nazara
My most negative experiences with people in tf2 is overwhelmingly in highlander and anyone who I've talked to who has played both agrees that highlander players are much more toxic than 6s players
Agreed, although I think that's mostly because new blood is usually more toxic compared to older more seasoned players and highlander hemorrhages significantly more top level players than 6's.