From an evolutionary perspective, a tribe/species that persistently favors homosexuality inevitably would increasingly experience barrenness among the tribe/species members, which would ultimately lead to the demise of the tribe/species. It is for this reason that homosexuals (whether those in the animal kingdom or in human communities) have always been, and will always remain a minority.
Having said the above, I strongly believe that people with homosexual inclination should be treated with respect and understanding, and should not be discriminated against, denigrated or demonized.
Nevertheless, realistically speaking, I believe we must acknowledge that there will always be a bias among most of us (many a times unconsciously or sub-consciously) for heterosexuality and against homosexuality, given our evolutionary (natural) instinct for procreation and survival.
The more we are willing to admit this bias wired in our natural brain, the better able we will be to address it and override it, with our rational mind.