It's a perverse incentive to drip feed small updates into crap games instead of making something that can stand on it's own. I have never played an ealry access game and thought "wow i'm glad this was early access", likewise i've never played a full release game and thought "this would've been so much better if it was sliced up and spread out over several years.

I say this as someone who loves 'library of ruina' which took a few years of early access before it was finished, I played after development was done and it's obvious the early game is gimped in comparsion to later game mechanics.