Because unlike you and him sexual orientation doesn't bother me nor do I find it makes any difference on a person's qualities.
There was a gay guy at university. He was normal, down to earth and mingled with everyone. No one gave a rats' arse about his orientation, nor should they.
Probably you didnīt get what I meant because with no means did I tell that someone who is homosexual automatically should talk about his/her sexual preference.
As much as my friends from university didnīt know about mine I didnīt know about theirs, only if someone asked about that I answered.
My point was that if you want to get to know other homosexual people (for example because you are looking for a partner) you have to be some kind of more outgoing than the average hetero man/woman has to be when he/she wants to get to know possible partners, because the possibility to find someone of your sexual preference at e.g. the birthday party of your friend or your working place is smaller.
So sooner or later you have to find enough courage to speak to people you completely donīt know, because there simply are no other homosexuals around you.
It is probably difficult for all shy people in the world to find a partner, but a shy guy and a shy girl probably get to know each other easier than 2 shy guys or girls.
When you are a more outgoing person that also is reflected by the way you speak to people when your own sexual orientation or the one from the person you are talking to is completely unimportnat, like in your case your mate from universtity.