OK. I'll start. The only thing I could think of is if Arsenal was overtaken by a sugar-daddy who whored his way to success by buying mercenaries and letting go of our loyal players. THAT would go against everything I believe in and only then would I probably stop supporting them.
After replying to a troll in a thread just now, I started thinking to myself, "is there anything that would ever make me stop supporting the Arsenal?". Whilst mulling it over in my head I wanted to see what other people might come up with. Football is a vehemently tribalist and loyalty is adhered to without question (at least on the fans' part). But what, if anything, could ever make you stop supporting your club?
Just think about it. I don't want to just read 10 responses of "NEVER! I'm X for life!!!"