TFA mentions the other costs that you're (potentially) not including: property taxes, maintainance, building insurance (depending on your escrow situation).

I think MB's point is that there's a lot of talk about how "investing" in home ownership is a smart financial move, and that a more careful consideration of this suggests that it's not so clear that this is true.

There are definitely other reasons to own, if you're of the right inclination (I certainly am).