I think you are absolutly right that the freerolls takes a lot of time and the payout is low. But I play just for fun and sometimes when I am in a gambling-mode, I enjoy the freerolls. I am not loosing money and its much better than play no-money chips games. And at least you can win something at the end.
Anyway I never got in the money in the freerolls (even after 4 hours playing) so I think everybody who gets some bucks can be happy and, more likely, playes finaly better than me.