Giving people reasons doesn't work. I once put a note through the door of someone bordering my mare's field to explain why she shouldn't be tipping cauliflower over the fence (brassicas can kill horses), and to ask her very nicely not to feed them again. She carried on.
Didn't stop until I called her gardener over one day and said 'can you tell your customer that since she has ignored my polite request to not feed my horse, I'm assuming she is happy to accept liability for the vet bill when the stuff she's feeding makes her ill'.
Had people there complaining that they couldn't reach her cos I had put the internal fence so far back from the footpath. 'We can't feed her from here!' 'Yes I know. That's the point'.
'But the children like feeding her'
'Buy them a horse then'.
Someone else messed around with her loose in the field and made her so headshy and aggressive she was nigh on impossible to catch and took to charging at people with her teeth bared. It took months of patience, retraining and nearly getting mown down to get her able to be handled around her head again, and to have her once more behave safely around my children.
Every time you interact with a horse you teach it something. If you don't know what you're doing, you are likely to teach it stuff which is dangerous to its owner, who will be unaware of what has happened until the horse reacts badly to something it'd normally be fine with. Just leave other people's property alone fgs.
That poor lady and her poor beautiful boy.
I honestly think part of it is that people assume horse owners are rich. In reality, many, and certainly all the ones I know, do very ordinary jobs, and just don't do the things other people do. Fewer holidays, new clothes, nights out etc. A fat little native that lives out, runs off fresh air and isn't shod costs less than a few new clothes a month and a half decent couple of weeks away as a family per year to keep, but people think it's a rich person's hobby, they therefore perceive the 'please don't do that 'as coming from a place of intended superiority.