I'd agree that they should. However, if someone's on the fence, pushing them in a productive direction might be something that serves our (well, pg's) goals, in which case it's not really about responsibility, but about pg's effect on others, something he will likely want to take responsibility for, at least to some extent.
Or, to lift a more succinct phrase, "lead us not into temptation". ;)
"Pushing them in a productive direction" could be something like "You've been spending a lot of time here. Don't you think you should do something else?"
But for all the people not on the fence, you're denying them responsibility for their own choices. I can't help but feel that your stated agreement with me that individuals should be responsible for themselves is empty if you support measures that take all choice away from them.
I don't really support measures that take away choices (I'm against having the site closed for X hours per day, for example), but I do support arranging choices and defaults such that the goals of the arranger are furthered.
