Parents. Especially new parents, and especially mothers, tend to go through an extreme protectionist phase where they see a need to protect their children from reality, or rather adulthood. Think like never neverland as their ideal for the child's future.

This mindset is quite beneficial for very small children that very much lack their own agency, and ability to make smart decisions or handle danger either physical or mental. But as the child grows it becomes less and less beneficial, unless society steps in at some point to curb this very maternal attitude they will succeed in imposing such things on society as a whole to the detriment of their children's long term social and mental development I will say.

I will blame women for the major share of if but I don't see it so much as a feminist issue but more so an issue of a failure to grow up themselves. Some people, men and women alike simply believe that the negative implications of society or even just the very concept of rudeness, crudeness, anything that makes them feel slightly uncomfortable themselves is so bad it must be removed. It's not a tenable path for any successful society.

Just going with the weight issue. It's totally possible to be far too cruel to someone who is fat, that is true, but it's totally possible to be far to nice to them as well. Being fat is unhealthy for you, but if you are allowed to be totally comfortable with being fat to the point that you just keep on eating like a pig and continue to gain weight, it will kill you. Like it doesn't matter if I'm nice to you or not, it will kill you eventually. Would you prefer to live in a society where we just let you go off and kill yourself like some dumb animal vs at least attempting to get you to live in a more healthy way? Even if that is initially going to be uncomfortable?

Similar attitudes exist around sexual violence and the like. Nobody is going to claim that sexual violence is good, unless they themselves are evil. But you will find the overly sensitive types throwing fits over very basic advice like "don't go outside by yourself after dark" "stick to well lit areas" "avoid anything that draws attention to yourself" "don't go to certain parts of town at night " etc. Advice that might be "especially" for women sure but that doesn't mean it doesn't also apply to men in some way. All designed to keep people safe and avoid situations where they become a victim. But the overly sensitive will cry foul, claim the advice is sexist, and that it's not their fault if they are out at 2 am drunk by themselves in skid row. Yes of course it's the rapists fault for raping you, but you made a series of very stupid decisions that put you into a position of danger. It's not sexist to point out danger and advise that you ignore it.

I think these people are just utterly unable to look at the dangerous world and see it for what it is. They want to stick their head in the sand and pretend they live in some imaginary utopia where the laws of nature don't matter, everyone is nice to them all the time, and bad things don't happen to them ever.