To me it's basically stealing. The misprinted price is clearly not what the store intended, which means it would not be a consensual transaction.

I'm in turn genuinely curious how this is not obvious.

Would you be comfortable doing the same to someone who accidentally omitted a zero on their used car sales price on Craigslist?

Well, whichever worker accidentally mislabeled it could have a really bad day, depending on how much money the store ended up losing.

That's fair.