It's hard to blame them given the state of the economy.
The only jobs available pay like shit, rent is through the roof, so if you move out you're going to spend nearly your entire salary with nothing left over to eat out or go on dates or whatever. What's the point? Might as well stay in mom and dad's basement playing Fortnite and not have to work in some McDonald Franchisee's little fiefdom.
When I first moved out of my parents' house 20 years ago, a person working minimum wage could comfortably afford a place to live here in Canada. It's not like that anymore. Hard to blame people for just saying fuck the whole thing.