Indeed, but that's up to them. it's on the default and the other side of the viewers can see the amazing dirt covering up all that goodness. However, it's totally worth it since you are fighting your best no matter how dirty your costume gets because situations like that. "You are not suppose to care." DOA world: They get cleaned up. So people need to focus on the game a bit more.
I was just half joking, it wasn't necessary a serious answer XD
Btw while the importance on the casual side is not excluding of the technical one (so the two things are not in constrast), I agree with you that the priority for a fighting game should be given always to the gameplay, of course.