I agree that zsh's default configuration sucks (and the new-user wizard is overwhelming). I would like the project to provide a more opinionated set of defaults to OS vendors; i think we are probably just nervous about breaking 30 years' worth of expectations, and so far nobody has really pushed for it.

But i do think the misunderstanding i mentioned is very common, as illustrated by the fact that the GP seems to think that OMZ itself provides zsh's completion functionality. It's also a frequent point of confusion with people seeking assistance on zsh's IRC channel.