TynnyriPheaaThis is like going on a football forum and being confused as to why there is one ball
Weird analogy. Football does not have player role limitations, except for the goalkeeper. This is probably what you meant, as that's a better analogy.
Anyway, your original analogy sounds like an appeal to tradition. Football also has all kinds of rule changes, despite the tradition of the sport. These rules are also often discussed.
Also, I don't think I was confused on the reason any class limits exist. I think that was quite clear when I explained the Medic limit: It wouldn't be healthy for the meta. If that's wrong, you can always correct me.
The "ball" in tf2 is the uber differential, so having two medics would be like playing with two balls.
Your mum played with my two balls last night.