I agree that Firefox's certificate warning page is much better designed. I'm not blaming 'dumb' users for anything, I was providing supporting evidence of the fact that when browsers make warnings easy to bypass, users will simply click right through them.
Absolutely. If I took issue with anything in your post specifically it was "Most users don't understand that there are potentially serious costs". This to me seems to implicitly blame the users for not understanding, whereas I'd blame Chrome for a UI that makes it easy for a distracted user not to understand. As developers we have a responsibility not to lead users into doing something dangerous just because we don't have their full, undivided attention.
I was mostly disagreeing with the general "blame the users" mentality apparent upthread and among developers in general, not with you specifically. I've edited my post to make that clearer.
