Everyones said good stuff already but i'll add my token gesture: More options innit?
Edit: Oh hang on, i just realised I do have something possibly worthwhile to say on this subject! Now I love my atemi, for many reasons: To end a confrontation, to enhance a technique, for kuzushi, for improving reflexes and for toughening up to others strikes.
Now, if your fighting super tough convicts who spend all day sitting in their cell banging themselves off concrete then ok, your atemi probably isnt going to bother them too much. however, the training that you have put into this area will also have conditioned you in some aspect towards others strikes. First defense are reflexes, you will have better reflexes from training with atemi. Second is moving out of the way, if you never practise atemi then you will have a handicap in avoiding them. Third is your response to the strike, if you get hit, what do you do next? If you are conditioned, perhaps not physically, but at least mentally to getting hit then you are in a much better position than the people who believe that they wont get hit and will then floor the other guy.
As a side point, if many people condition themselves against strikes,you can of course also condition your striking parts (hands, knees, elbows, head) as well. But im sure we all know this already.
If any convicts are reading this then I apologise If I offended you with my portrayl of you