They should but only 40-50% do, I write "Ask for ID" on the signature portion. The ones that read it, ask me for it. Better than a signature that a cashier won't question anyhow.
I was curious about this and browsed through their operating regulations. It says something to the effect of "Visa considers a signature box that only says See ID to be blank".
So the pedantic response to your second sentence is that they consider the See ID irrelevant (and once there is a signature, it is apparently a violation of the merchant agreement to ask for ID, but I didn't look for that in the operating regulations).