yes and no
If you hammer a flat surface, that's definitely bad. but then same same for a keyboard.
If you learn enough control of your fingers to maintain a light touch, then it's OK. I use a scissor-action/short-travel (laptop-style) keyboard because the pressure+impact of a standard keyboard is too much for me - keys that push down also push back, don't forget.
The advantages of not having a mouse (reaching off to the left/right to reach pointing device from your centre position is Bad), scrollwheel and other RSI-nasties probably outweighs the potential disadvantage of no key feedback.
iirc, the fingerworks board had a bit of give in it. not that I ever got to see one, thanks Steve.