I'm honestly not trying to be offensive, but one of the main reasons for the perceived "bad rap" bc you disagree w/what's popular in society is bc it's still a contradiction w/what the Bible actually says and many people find that hypocritical. You (not just "you" specifically, but you in general) allow the makeup, the tight fitting clothes (even if only for one routine), any non-Christian music, etc. still goes against many of the main principles and/or tenets of Christianity. You simply cannot pick and choose what's ok for "you" according to the Bible, but not for these other Christians in accordance w/the same Bible.
I personally don't believe the Bible is open for a lot of interpretation. Despite mine and my husband's difference in beliefs than our families (his dad is a pastor and I grew up Southern Baptist and my mother grew up Pentecostal), I do see the example my father-in-law sets as one in accordance w/the Bible's word, tenets, etc. He won't listen to ANY music other than Christian music, he used to throw away his children's CD's when he found them, he wouldn't tolerate swearing, no cable in the house, not radio except Christian AM, etc, etc. Yet his heart is full of love and he is one of the most kindest, honorable, and respectable men I know and his heart is genuinely one of nothing but love. He is living by example they way the Bible says. It's not really "with the times" and religion evolves. Now it's ok for people to accept some parts and willingly disregard others. I think that's the problem that many people have bc they feel it's hypocritical.
I'm not judging you bc I don't believe that way and I don't know you from Harry...but I think if you honestly think about the things I've said, you will understand where I'm coming from in answering your rhetorical question. No one expects Christians to be perfect (at least not most people) simply bc you're Christians. It's the picking and choosing which parts you accept and which parts you disregard. I would have to imagine that Jesus wouldn't find cheerleading "acceptable" (on so many levels) or a beacon of showing his love and what he/Christianity is all about. Heck, my late granddaddy would have a heart attack bc of the makeup and uniforms alone! They weren't allowed to wear shorts. But anyway, I think it's perfectly within your rights to be as conservative as you see fit and for a gym to operate in any way they see fit and I admire anyone w/standing up for what they think is right and trying to show a good example, but I also admire the other gym/people anywhere else who choose to adhere to what they feel is acceptable for them. Finding the balance between the two is where I tend to see the most problems on the extremes of either side...If that makes sense. :)