I understand what you're saying, but speaking only for my child, we did have to choose. She came to this sport 3 years ago not even knowing how to do a round off, after playing travel softball since she was 5. It was only supposed to be an intro tumble class during a 2 month softball break.
We did both the first two years, but it did get to the point that we had to make a decision. Not just for her- but for her teammates. It was not fair to her teams for her to miss practices, ballgames, or competitions. We make a 3 hour round trip drive to cheer and it doesn't leave a lot of time to do other things. Even if we were close by, there would still be problems.
We pay so much money to do this, and I will admit that it really ruffles my feathers when we can't practice stunts or the pyramid because the same kids repeatedly miss practices because they want to play volleyball, do school cheer, be on the track team, try out for drama, etc. You know the amount of commitment it takes when you sign up for this very expensive sport. In my opinion, if you can't fulfill that commitment to your team, you shouldn't sign up.
I realize that is probably not what you're talking about- if your kid is able to do multiple sports without missing practices, games, or competitions, then I think that is great and should be encouraged. It has just never worked out that way for the cheer teams we've been on. There is always conflict. And it almost always drives our coaches insane.
Sorry for the mini-rant. Nothing personal and I didn't mean this to be aimed at you. I'm mainly just griping about some of the parents/kids in our gym lol. :)