I do think that is a better analogy; borrowing your neighbors shovel without asking is likely (depending on state law) theft, regardless of how well you and your neighbor get along; if your relationship is good, it is likely considered acceptable, and so your neighbor won't press charges. (It's still legally wrong, but won't be a problem.) If, on the other hand, you don't get along so well, you're likely to wind up in some measure of legal trouble.

Which is pretty much the deal with wifi; in many states, it seems technically illegal even the wifi is deliberately left unprotected out of goodwill, but you needn't worry about it.

The whole analogy did not seem to me like an argument that all unprotected wifi is, and of right ought to be, free; I took it differently.
On the contrary, I think some of them are not in defiance of logic at all; but they do tend to defy law, and all too many fail to apply logic well.

After all, you made your appeal to commons, but that was an appeal to a historical (hence derived in ignorance of wifi) legal concept, not logic applied to the current situation. It is possible that a logical analysis from correct premises (which there's no agreement on) would show that all unprotected wifi should be free. It's possible, given enough time, and effort from pro-free-wifi and pro-WPA groups, that the laws are changed.

I think anything defying (current) law, but using logic, is perfectly reasonable to have around. It's part of the democratically-structured way of changing laws here; but it should be recognized as either that (hence not applied to practice, until the laws are changed), or willful civil disobedience (with the intention of getting caught and thrown in jail as a means of protest), if you're into that.