Immoral? Unethical? Hmm, who decides those i wonder?
Get to know a gay friend, and ask why they become gay. Most likely,
the answer you get is that they ARE what they are.
There was NO CHOICE at all. Just like you are straight when you are
born.
As for why there are guys that dont like girls...well isnt it
obvious?
straight guys like girls because they get reactions (or
erections..) when together with a girl...while gay guys...you
figure it out 
