Why are so many people against piercings?

I never understood people's hate towards them. But then again, I'm an extreme piercing/body mod enthusiast, so yeah. But anyways, what makes them so unappealing to you? To me, they're just a way to express yourself. Y'know, we were given this body, so we should be able to do what we want with it, to make it our own, whether that includes getting tattooed, or getting a piercing.