I understand your point that by postworking it doesn't actually show the "real" output of the software. But I wouldn't say it's misleading or deceptive. Yes it's like all advertisng - and yes everyone does it. It ain't gonna change.   

momodot - don't be naughty thats not a poser render - she has no sword :)

Pinky - you left the lens cap of your mind on again.