Which is beside the point. It wasn't supposed to be used for body text or print in small sizes. And it doesn't have to be hinted because it's not meant to be used for long form screen text.
Would you call a title font "bad" because it's not suitable for body text?
As for it "not even being a true sans serif", there are several fonts that cross those boundaries while being perfectly fine. Not being a true "sans/serif" is not some badge of dishonour.
Comic Sans is a good font because it is perfectly suited to convey the message people use it for: child-like, friendliness, common folk-syness etc. As such it's great for personal posters, party invitations, signs, yard sales, elementary school signs, etc.
Notice that even if that wasn't the usage intended by its creators, it's still a good font, because it found it's own niche.