It's a fair analogy and no, I couldn't afford to pay a year's education up front. You'd be surprised how many parents that send their kids to private school aren't hugely well off - we've had to make many sacrifices to send her to the private school (like not going to Saints as often as I'd like - true story that, not just me stirring things up!). I fully expected to find a school full of kids whose parents lived in mansions, drove posh cars and had several villas in the Med but they are actually few and far between (much to my annoyance as I was looking forward to my daughter making friends with all these millionaires so that I could have free holidays for years to come!)
But back to your question.....if the school said to me this summer that they wanted all of the next year school fees up front before the start of the Autumn term I would first explore the 0% credit card option (indeed, this was one of our funding options a couple of years ago when myself and Mrs Trousers were first discussing our financing options). If that didn't work then I'd look at as low as possible interest bank loan and if that failed I would have to look at relocating her into a state school.
Either way, I don't think I'd be kicking up a huge fuss about it as the school is a private company and they can ultimately do what they please. I guess where the analogy breaks down is that I don't have an emotional tie to my daughter's school in the same way one does to a Football Club.