Wow... our dojo must go through un-healthy spurts then, because for a while, just about everyone was taping up a wrist, foot or something.
I've always made a distinction between self-inflicted injuries and other-inflicted injuries. Maybe it's not that simple, though. I can easily imagine a situation where a lot of self-inflicted injuries could indicate a bad training environment (unsafe practices, people not being taught how to respect their bodies' limits, poor fitness levels, whatever). I wouldn't really look at a dojo and say, "Lots of taped up people? REJECT!" But if you see that everyone seems to be taped up, it's probably good to look closer at the reason why.