It isn't shade its reality. Until you have a child of your own, you don't realize what "I would never" really means or the impact it might have on a child. Judges DO need to see athletes faces and the reality of this sport is that presentation and perception matter. You can argue that it shouldn't all you want, but until the perspective of judges, gym owners, the fans, and yes even the parents shifts it will be what is expected, and you either fall in line with that or find another sport. Is it really fair to let a preconcieved notion about eyeliner that I had in my 20's stop my child from doing what has become her passion?
Gyms expect you to follow the rules or hit the road. Saying "I'm not putting makeup on my kid" just isn't going to fly. They will show you where the door is. Just ask "hairgate" mom. It is not the only place either. We have done it for dance since she was 4. It is what is expected to participate, and you either do it or don't dance. It isn't worth denying a child the ability to participate.
So sure, work to change the perception, and change gym owner's opinions about makeup but don't come on here with a superior attitude and say "I would never put makeup on my child" like all of us are idiots or bad parents for doing it when you don't even have a child that you need to make this decision for. It's easy to say you would never do it until you have to decide between putting eyeliner on your child or them not being allowed to cheer. It's not as simple or black and white as you seem to think.