Do you leave your nuts and caps on your tube stems? Why?

Of course it is road only and I would put the caps on if it were off road.

Whenever I replace a tube I do not put the nut and cap back on. I was told my LBS that it was just extra stuff that wasn't needed.

I am curious though, why do the manufacturers take the expense of having them if they are not needed. But I have rode thousands of miles with out them.

Your opinion please!