Molly people discrimminate against others, and denegrate others, to make themselves feel better about their own pathetic lives. I copped this all the time as a very young single mother. I had a woman on a bus (these people like to hang out on buses, me thinks), tell me that she didn't want her taxes paying for the upkeep of someone who couldn't keep her legs shut. This woman had no idea who I was, or what my circumstances were, she just assumed that I was promiscuous and on welfare, neither of which was true, but I'm sure it made her day to feel superior for a while.
My very dear friend has a weight problem, which was directly caused from birth control hormones. When she worked out what was preventing her from losing weight she got rid of the cause, but it has been a long road back for her. She has recently started on the bitters and is finding this a great help for weight loss. You are dead right when you say this is nothing to do with character, or the abilities of the person. In our shallow society that is obsessed with appearance and 'image', judging people and criticising people is the norm.
I prefer the buddhist way, "be slow to judgement and quick to compassion" .