My mother once told me a story about a couple she knew, when she was younger, who invited her over to dinner one day. She said they were nice, healthy, intelligent people that she'd known for quite some time, and was happy to accept their invitation.
So she got there and had dinner, and everything was mostly fine; except she had to sit and watch as her hosts forced their obese son to finish everything on his plate before he could leave the table.
I think that experience may have turned her off the idea, because although I was encouraged - strongly encouraged when I was a young'un - I was never forced, like some of the people in this thread have been (except when we were visiting at my grandma's house, which may well be another reason my mother never did it to me).
I'd like to criticise the practice as abusive and sadistic... but most people who have it done to them grow up normally, whereas I am dangerously underweight. So I'm not really sure where I stand on the matter.