Fade outs can be very creative, like fade in's, I heard a fade in the other day that blew my mind, and I'm going to borrow the idea on my next tune.
Fade outs can surprise, re iterate a reprise, I love them and think of them as a real opportunity to finish the song in a way you least expect, I agree it's obvious when people are lazy and just fade to black, but if you can make them smile or surprise that's worth it, I think of it like the lingering 'Finish' of a good scotch, it's there way after it's gone.
cpm