Perhaps I confused the issue by introducing the word "uncertainty." I'm happy to drop that word.

You started out by saying "The reason why perhaps not push the button: unforeseeable (?) unintended consequences." My point is that there are unforeseen unintended consequences both to pushing and not-pushing the button, and therefore the existence of those consequences is not a reason to do either.

You are now arguing, instead, that the reason to not-push the button is that the expected consequences of pushing it are poor. You don't actually say that they are worse than the expected consequences of not-pushing it are better, but if you believe that as well, then (as I said above) that's an excellent reason to not-push the button.

It's just a different reason than you started out citing.