Sadly though there are some idiots who DO hate the other club and fans etc but Id say they are the minority and no reason to spoil everyones fun.
Yes, that was my point and I'm glad you acknowledge it. Well, not glad, I'd rather such attitudes didn't exist obviously but glad we're in agreement about it.
I was a regular at Leicester City for a number of years many years ago. I'd meet up with a bunch of people pre match for a drink etc. I loved the humour, the piss taking, the gentle rivalries. It was, as you say, part of it all. And yes, rivalry and hatred are not the same.
As a Leicester supporter, you were supposed to 'hate' Nottingham Forest. I played the game obviously but actually used to really like to watch Forest (under Brian Clough then) play. One of the most complete and attractive teams of the era. But I'd never actually say that, that was serious and not part of the laugh you were having. So I'm kind of aware of the pretend hating, if you want to call it that - the craic to use Irish expression.
But there were nutters that did hate, and genuinely so, as you say. I couldn't understand that and still don't. But I wasn't born and raised with it nor was I part of that environment.
Obviously, both rivalry and hatred exist across the world. I wasn't suggesting it was only a British trait. The British do though, ime, have a cynical and negative humour (I don't mean 'negative' pejoratively btw, and I wish I could find another word). I only meant to suggest that perhaps that humour sprung from the same place as the delight in a team's defeat - where the person is neither a supporter of a rival team, nor even a fan of the sport.
On an emotional level, the results of Man U don't effect me. It's interesting in terms of the footballing dynamic (if I can phrase it like that) but they don't make me smile or cry. I can understand Man C (and maybe Leeds) taking pleasure - and obviously fans of teams around them in the table - but not really wider than that. And certainly not people who don't even follow football. That, I simply can't understand. I obviously appreciate that it happens but I can't work out where it comes from.