To my way of thinking, that's called 'grooming' and I do it all the time. There may be times when it isn't appropriate, but I don't know of any. Of course, if you get too many bad leaves you might have a bare stem, at which time you could cut it back and root the top with the leaves. I do that all the time, which may be why I'm so popular at our plant club exchange--I always have lots of plants to bring, and I'm very grateful to them for taking 'em off my hands!