It has nothing to do with being proper, excessive use of proper dithering is still excessive use... The problem is that people want to use their new skill and not just let it sit on the back burner for months until that one opportune time they actually need it(like dithering). I hardly EVER use dithering, and when I do it's a very, very subtle effect.

IMO if a new pixel artist never learns dithering, I don't feel they'd ever be at a disadvantage. It's just not that useful of a technique anymore with LCD monitors being much more prevalent. AA and proper pixel clusters are much more widely used and advantageous techniques to learn in the field of pixel art.