Most full stack devs I've met are crap at one end or the other. I've also noticed a lot of el cheapo companies trying to get away with full stack only because having specialized devs costs them more money.
These companies would love to fire everyone and have DevOpsQAUxPmUiExec do everything instead.
Yeah I can do frontend stuff in a pinch and it'll mostly work but I wouldn't call myself a full-stack developer because I'd be taking the piss out of people actually doing frontend properly.