It seems like the "it has no impact on me, so why do I care," argument is used a lot these days. There may be a lot of actions that don't take any food from my table or clothes off my back today, but if they are doing something crazy and it's being passed off as normal, it could impact impressionable minds. If something is thrown in their face often enough and loud enough, soon there will be no such thing as strange or unusual to them; everything is normal.
As for the more technical side, it's not as if every doctor and psychiatrist has lined up with the belief that it's normal. There are those who believe it is a mental disorder that it causes ones perception of their physical self to be distorted. That's what happens with anorexia; no matter how skinny the person is, they have a perception that they are overweight. If that is the case, it doesn't help that we now have a poster boy for it making it seem so normal; no therapy required.
I also hear the argument a lot about "if it makes them happy." Is that a true measuring tool for whether something is ok? I'm sure there have been a lot of people perform all kinds of weird and horrible acts that were happy about it. I'm sure we all had ideas in our youth that we thought would equal happiness, but later discovered that it did not. So, I'm not so sure doing everything that I think will make me happy is always the only aspect I should consider when making a decision.