I think for many us, falling out of love for the game has been a long and slow process: but in all sincerity we should have seen it coming. Like others on here I too am a bit long in the tooth - 63!
I have fond memories of how the game was all those years ago, it was for the working classes in those days. Grafting all week then off to the football on a Saturday afternoon...bliss. But when the money started rolling in, around the mid-80's, probably, it changed. The rags were buying anyone and everything and nobody else had a chance to compete. Refs, linesmen etc, all going out of their way to ensure the pisscan got his way. It wasn't football anymore, it was one extremely rich club lording it up over us others. And with that nasty jock bastard in charge, coupled with a fawning media and thousands of plastic Asian supporters everywhere in their club shirts, my dislike turned to sheer hatred for the club - but mostly hatred for that fucking poisonous Glaswegian and his odious hangers-on.
But the time I really thought of giving it up was taking my son to Elland Road (I think we lost 3-2) and the sheer hostility we encountered from their supporters, and the threat of violence hanging in the air put me off ever going to a game again.
It might be an age thing, I really don't know. But I've had a burning resentment towards what has happened to the game I've loved all my life because it is not the game that I grew up with.