i think alot of tf2 coach/newbie pugs forces newer players to play in a very rigid playstyle,players running sniper's/pyro's near fulltime is completely discouraged and while I agree with that somewhat to kind of give them an intro to 6s, it does the opposite because when I first started playing I played a couple matches in UGC against teams that ran full time pyro, heavy, and sniper and we got demolished
i'm extremely biased about this because I love to play sniper and offclass heavily but when you play low level pugs you get warned/banned for doing things that are completely legal in matches
i think weapons that are banned (i.e cleaver, jarate) are banned for good reason and i don't think changes the game that much for newer players but forcing new players to have the same plays and run the same things over and over again with no offclasses or banners is just setting them up for failure