This forum is becoming too much of a pyro/heavy hating circlejerk. I get it, you won't see them in your beloved 6v6 99% of the time and if you did, they would make the experience worse, so they're irrelevant to you. Doesn't change the fact that they are a part of the game, and TF2 wouldn't be what it is without them. And with the competitive update coming, it's likely you will see some pubbers trying out matchmaking and playing pyro and heavy all the time because it's their favorite class. And if you get all condescending about how pyro and heavy is cancer, you will discourage them from competitive.
(plus who knows, maybe the rebalances in this update will make pyro and heavy have their place in competitive too, you never know)