And a player can give the ref the ball without being a robot.

I have seen celebrations that are not simply having fun, in which they are classless and can instigate fights between teams. Not regulating celebrations also gives people license for obscene and crude things. Not saying there should not be celebrations and teams DO celebrate. We see them. THey are not just walking to a funeral and you likely know that. See all the teammates mobbing each other in the endzones.