Not my thing either - actually, I wondered briefly whether the site was too football-y for me... but as others have said, whilst it's a significant part of the chatter here, it's not the main event; just a vehicle for getting off backsides and do something healthy and fun for those who like football.
Ive mostly read the forums quietly since joining and haven't played, but the advice and encouragement is excellent, as is knowing there are other people In the same boat. In fact, I was ready to give up after two days of healthiness and some people I'd never met picked me up off the forum floor and kept me going. I'm hugely grateful for that and I'm now nearly a month in and going strong. Absolutely nothing to do with football!
All that said, I do think finding a thing is important - I'm rather enjoying jogging (in the vaguest sense of the word) and cycling (slowly) but it doesn't matter what it is really.
Maybe there's room for non football MvF teams that follow a similar model to football but walk / run / jog / cycle / tennis / whatever instead?