As a small kid, my parents never abused / humiliated / punished me in any way for diapers / accidents. Honestly, my mother had me out of them so early that I don't have any memories of being in them. I do have a few faint memories that had to be from that time--one faint memory of my mother doing the wash and putting diapers through the wringer of the old washing machine, and another of me sitting there watching her fold diapers and they HAD to be mine. But, no memories of sitting there consciously thinking "I'm wearing diapers". So in my case, that had nothing to do with me growing up to have this fetish.
Or--if it did--in my case it was completely the opposite: I do think that being out of diapers so early did cause me to be envious of the other kids who still got to wear them and who still had accidents. And there were many and they were all girls--younger cousins and kids in the neighborhood--who did. One in particular, a girl about my age who lived next door, who intentionally wet her pants until we were 5-6 years old and (I later figured out) was diapered at night at least through Third Grade (when we moved away).
I'd see her wet her pants a lot. On one occasion I went to her house and she was sitting on the porch in shorts/panties in a big puddle of pee, very much enjoying the fact that she'd had to go then sat down and intentionally peed in her pants. This prompted me to begin my early experiments with wetting. I'd say I was about 6-7 years old at the time. And THAT'S when I did experience some humiliation--there were a few times that my parents found my peed-in underpants and it was "If you don't stop doing this we're going to put you back in diapers!" But by that point, that sort of discipline was appropriate. (And secretly, I almost wished that they would. Ha.)
About this same time, I made the mistake of telling the kid across the street--my best friend at the time--about my fun habit of sneaking down to the basement and peeing in my pants. He then blabbed it to the other kids and for a few weeks I was relentlessly made fun of for this. Also about this time, a kid in my Second Grade class pooped his pants at school and I then just HAD to go home and try it and when my parents caught me doing that, I REALLY got in trouble.
And that's why I quit doing this for a while, until I was about 11, was entering the early throes of puberty and discovering girls. That's when I started visiting the girl next door, going to her bathroom, and smelling her panties. I know that's a controversial subject around here, but I admit I did it and loved it, because this particular girl's panties had big pee stains in the crotch. This brought back memories of my early wetting fun and had the added element of "girl" added to it. Then I found out that the older sister of a friend across the street--who was in high school--still wet the bed and on several occasions I found and "enjoyed" her wet sheets and panties in their basement. It wasn't long after that when I started wetting again and that quickly led to the diapers--there now was a very sexual aspect to it, and I've loved it ever since.
But it had nothing to do with being mistreated by my parents or any other adults.
I'm sure that the vast majority of those who WERE shamed in this way absolutely hated it and did not grow up to have diaper fetishes. But of the handful who did, many probably enjoyed what they were doing at the time, secretly longed to be back in diapers, and longed for everyone to know it. As adults, there are lots of us who love our diapers and constantly experience what I call "the diaper dilemma"--half of us wants the entire world to know that we love wearing and using our diapers, while the other half of us is scared to death that others will find out that we love wearing and using our diapers.
For me, this "ongoing tension" is what has often prompted me to go out in public in diapers, scared of being noticed while secretly WANTING to be noticed and even laughed at. Because, that means that for that one instance, with the people who notice your diapers and giggle at you for it, the 'cat is out of the bag'. You're in public in your diapers, other people know that you're in your diapers, and for a brief second, you're truly free and being who you want to be (a big baby) and it's great.
Now, that being said, I should point out that I don't do this often and no, I'm not trying to shove my fetish into other people's faces. I'm careful about when and where I go and who may notice (for example, I always go during hours when kids are in school). I always dress in ways that it's obvious that I'm in diapers--IF YOU LOOK CLOSELY--but otherwise most people never even notice. The situation is always such that, 1) there's no way for them to really know if I'm doing it for fun or out of necessity, and 2) though I love it, the act of them staring at / giggling at me is very much an act of them invading my privacy and I don't think that's any worse than me going out in public diapered in the first place.
Well, anyway, those are my thoughts on this topic. Thanks for asking.