He doesn’t dress like that to visit schools. He’s not dressed like a little girl, he’s dressed like a conventional older woman. So that’s just a straw man argument.
Dressing like a little girl or dressing like a woman is a sexual fetish for him. He's getting a sexual kick out of people being discomfited by his presentation. To the point, where the clothes he wears have to accommodate his erection.
If a child, later on, discovers that all the adults around them encouraged a man with a well known sexual fetish, who gets off on shocking them, to enter their orbit, don't you think that is wrong? A terrible violation of safeguarding? Of trust?
Also I don’t think it’s correct to say he finds the idea of little girls sexually humiliating. What he finds humiliating is the idea of himself being dressed as a little girl.
He finds the vulnerability of little girls being overpowered sexually exciting, if he imagines himself to be one.
It’s the emotional scenario of being overpowered and humiliated that’s the turn-on.
This is a man, who has managed to convince everyone that his overwhelmingly male and incredibly public sexual fetish, involving men women and children, is fairly harmless.
Vulnerable he isn't.
It's a similar thing that many AGP men describe as sissification.
The idea that women are there to be subjugated and they can leverage that for their own sexual pleasure.