With the exception of people expecting to deal with explosions(where bunkers are a natural fit; and fairly commonly used in varying degrees of sophistication); a lot of this disaster-prep stuff falls into an unhelpful category of being both overprepared and underprepared: If you are concerned, it's pretty easy to justify enough supplies to weather a breakdown in our efficient-but-tightly-stretched supply chains; but you don't usually need a bunker to do that. If you have a crisis more serious than not being able to buy groceries for a few months in mind, however, the problem stops being "Do I have enough MREs?" and turns into "Am I set for subsistence farming and/or tribal warfare; and do I really want to bother with that shit anyway?" unpleasantly quickly.
It all seems aimed at a (not impossible; but not necessarily plausible) medium-size disaster; which will somehow be big enough that the 'stash of supplies in the basement' crowd is doomed; but small enough that your bunker isn't going to be plundered by local militias and there will be a society worth living in waiting for you when it's time to open the door again.