Technically, my main put off was manwhore's typical ignorance on any subject physical(mma, bodybuilding, powerlifting, olympic lifting and probably football, but namely the first 4). But, Phreezer did hit on at least one aspect.
You should just come out and say it. There's no shame in it. Say, "I'm a shirtophobe. I hate shirts and all other pl equipment and there's nothing you can say to make me believe otherwise. My predjudices are ingrained and unchangeable. I will find any small loophole possible to make shirts terrible and all other athletic equipment acceptable." Just say it. It's alright, we won't hate you.
And don't take me the wrong way. I'm not trying to be a dick at all. You're clearly an intelligent fellow and I'm glad to see a non-moron present on the board. In fact, from what you've shown here, I think you might look into studying philosophy. I think you would like it and be good at it.
However, you've shown a complete lack of effort to even consider the other side of the argument. I love to argue(I've got a degree in philosophy myself) but it makes no sense to argue with a stone, since it can't/won't change. Unless you are willingly to objectively consider the other side, then the argument is futile.
For instance, at one time I was a flag waving commie, pinko bastard. Then I read "Atlas Shrugged". I said, well, geez, that's a pretty damned good argument right there. I think she's right and Marx is wrong. Thus, I changed my mind.
You, on the other hand, have proven to be unreachable through rational thought. You claim a shirt is as active as a spring, which has kinetic movement whereas a shirt doesn't, and everything else that enhances athletic performance isn't. Even when such things as a pole vault DIRECTLY increase the ability of the athlete. Even if you argue that such is the nature of the event, so, too, is equipment part of the nature of today's powerlifting competitions. The point is moot. Morevover, there is no activity present in a shirt. In fact, it makes activity hard to do. But, I haven't spent too much time defining the terms here, so I will stop so that I don't make a lame argument.