Okay, but if a user went to a http version of YouTube and put in your payment info to buy a movie, as opposed to remembering it should take him to an https Google page, I would find that a plausible situation that is hard to blame the user for. Attackers being able to hijack the reputation of sites is problematic.
Youtube does not have 0 reputation. The point of this thread is arguing the merits of requiring sites that don't handle sensitive informationfto use https.