I'd be up for an ongoing O/T philosophy thread if you are keen IBS, seriously
In answer to this, yes on the face of it supporting football's a bit pointless in that it doesn't immediately keep you alive...but then so are most other things
But I reckon it actually does some good - I think you need a distraction now and again to be able to concentrate on more 'life and death' or serious matters when you need to. Also good to admire skill and sit around and appreciate others' views on things.
In answer to the original question - my theory is that people like or are sympathetic to individual persons or groups they have something in common with, but aren't all that fond of 'people' ie humans in general if they don't know them directly. Those that are helping each other in crisis now probably wouldn't be so caring in daily life by being sympathetic to others' views or being selfless when they don't have particular knowledge about their situation.