You are obviously missing the point. I have not even addressed the issue of an injury from falling, although the chances are much greater if one plays a contact or high impact sport sport on concrete. It isn't a matter of being a "sissy," it is a matter of common sense. One doesn't doesn't jump off a roof top to prove they are not a sissy either. An exaggeration, but the long term effects of playing basketball on concrete would be just as devestating, if not more so -- depending on the height of the roof.

The broader issue is children, who 15 or 20 years down the roard, will have major knee and joint problems.

I suspect not a single professional basketball player would even consider playing any serious basketball on a concrete surface.