Will one counter example do? Have you ever met Apple fans? No, I did not say customers, I said fans, supporters. Maybe IBM doesn't have them, Apple does.
They will buy Apple products no matter what they are. Seriously. And if they get let down they will still always buy the Apple product first, before getting something else.
You seem to think that tribal attitudes only exists in sports and that's a fallacy. They are much more widespread than that.
I've never really met a true "Apple fan", where all they do is talk about Apple products while fiddling with their favorite Apple toys. Many people do buy Apple products, but that's more due to the fact they're cool electronics and materialists want to show off among friends. A fad, so to speak. So "fans" of Apple are not really true fans, but delusional people who will end up doing themselves harm by not buying the better product.
Contrast this to football where there are thousands of clubs across the world. If football clubs were similar to Apple or Microsoft, then only Real Madrid, AC Milan and Manure United would exist.
Football is obviously much more than that. You seem to be forgetting that for millions around the world, football is their pastime, or perhaps all they have. All you need is a friggin' ball, not a $24857473733 iPod.
That is not the point. Yes, the club falls apart if the fans don't support it. So does a company if the clients (or fans) desert it.
The point here is that "the club" is a fictional entity. It doesn't really exist. The people who ran the club 50 years ago aren't there anymore. Not a single person remains. The only thing that remains is the badge, the name, the brand. Now, if someone says to me "you should respect Barcelona for their historical whatever", my question is "Barcelona who?". The people who worked for the club back then? The fans back then? The players? Which "Barcelona"?
As long as we're talking football the symbolic idea of a club will suffice, because we all agree that's what it means, even though we know that one group of players doesn't equal another. But this is the only way to keep score. But when you start talking politics, social issues etc I'm not satisfied with a badge. A badge doesn't do anything.
Social issues? Politics? Hah, tell that to the fans at the Dinamo Zagreb - Red Star Belgrade riot, the match that basically symbolizes the start of the Croatian War of Independence. You seem to be out of touch with how much football means to some people, or a people(s), where almost everything they do is based on that one beautiful game.
A badge might not mean anything to you, but in some cases it does symbolize a group effort in one quest or another.