That's mainly because in the real world there aren't any tk-ers (that i've ever heard of) on the levels of those in comics. Therefore, the boundaries are set by the comic book writers. People will always look down on you if you try to find a real-life equivalent or anything like that. It's called ignorance, and i'm afraid it's all around.
I was thinking a while ago about a new way of looking at TK. Like another kind of energy, which is not shown to the naked eye, that can be manipulated by certain characters.