Honest answer to the stupidest interview question: my biggest weakness is that I need a steady supply of currency to keep myself and my family housed and fed—is the vulnerability that got us to the point where I have to answer these questions and pretend that I really really do want to productize whatever needless software widget you’re selling.
*ahem* Sometimes I take my work quite seriously and advocate passionately for my favored set of professional values even after the decision has been made.