I am completely with you that I exercise and try to stay fit(lean, healthy, whatever you want to call it) for vanity and performance reasons. I want to be able to lift heavy things compared to my BW and I want to look good. Even if those things are counter to my health I would do this and in some cases they are. As I know you are familiar with as well, RSIs, tendonitis and just general aches and pains from certain lifts are pretty common.
Now, I do feel better overall than I did a few years ago when I was out of shape and miserable. Doesnt mean everyone would feel the same, some people probably get sore from a workout and decide that exercise isnt for them.