Ellipsis - "Is someone's sexuality important then? Should we all be taking note of each other's individual sexualities - not simply prospective or actual sexual partners, but also friends, enemies, relations, colleagues, acquaintances and people we don't even know, e.g. celebs? If so then for what purpose, please?"
As far as people in the public eye - and this obviously includes Tom Daley - there is a multi-million pound industry devoted to examining every minute detail about the lives of the rich and famous, because that is the culture in which we live.
Is sexuality important? Not in the true sense of the word, no, but in the wider picture, which includes the celebrity culture, such matters are seen as deeply important.
So in the real world, sexuality is not, and should not be important, but in la-la land where 'celebrities' live, it is of keen interest and a topic for discussion.
The purpose? Gossip. It is the more sophisticated version of tribal linkage - in ape tribes, they do it be grooming each other, in human society, we do it by gossiping, and a lot of people do it by gossiping about celebrities.
I am not someone who does it - may you are not either, but millions are, and do, and for that reason, Mr Daley will be tabloid and magazine fodder for a few weeks until the novetly wears off.