"I'm sure a lot of this Disney hate is down to snobbery or jealousy."
Definitely not. In fact, I was wondering the opposite, and if there's a bit of Emperor's New Clothes about it all.
Growing up in the 80s, Orlando was where all the richer kids at school went on holiday. They'd come back with fancy American sweets, and Mickey Mouse-shaped pencils. Hence my generation all thought it was THE place to go, and swore we'd go there as soon as we were old enough to afford it ourselves.
And then we grew up, got jobs and had kids ourselves. And wanted to take them to the place we' dreamed of going as a child.
Then, when you do go, and realise it's actually the same old Alton Towers/ Thorpe Park shite, only in a hotter climate, it's hard to admit it.
So people may then pretend it's the best place on earth and the holiday dreams are made of, and thus the whole cycle starts again.
It's difficult to spend 3k or whatever on a holiday and then admit that it's far more fun to go camping in the UK.
But FWIW, my week camping in Cornwall this year was a thousand times more fun than my week in Orlando a couple of years ago, and a fraction of the cost.