The social "norm" of heterosexuality is oppressive to alternate lifestyles. Who is to say heterosexuality is "normal" and alternate sexual lifestyles are "not normal"? Only a bigot would make such a claim. Nobody should cast judgement on another person simply because he/she practices something different. Humans are complex creatures and our diverse sexuality is one reflection of this. All sexualities are equal and, even though some sexual lifestyles may be practiced by a minority of the population, this certainly shouldn't make them less acceptable.
Unfortunately, our bigoted heterosexual society marginalizes, mocks, and oppresses alternate sexualities. During the past 40 years, a campaign of tolerance has helped this situation somewhat. However, tremendous oppression still exists towards those practicing alternate sexual lifestyles. The only way to end such discrimination is to normalize alternate sexual lifestyles by vigorously promoting them. By drastically increasing the numbers of gays, lesbians, bisexual, and transgender people in society, we essentially normalize alternate sexualities.
Ideally, in say 40 years (roughly two generations), we hope to realize a society in which at least 50% of all people are gay or lesbian. In slowly building up to this 40 year mark, we incrementally will (year by year) make alternate sexual lifestyles become more and more normal. Such sexualities will eventually, by definition, not be "alternative" but rather normal (due to the large percentage of the population practicing them).
TEACHING ALTERNATE SEXUAL LIFESTYLES
Older generations are a lost cause since they are typically set in their beliefs. This is why it's imperative to focus our efforts on teaching the newest generation (children) about alternate sexual lifestyles. It is critical that we teach children about all sexualities at as young an age as possible. Why? Because the younger a child is, the easier they are to reach. Waiting until a child is 8 or 9 (for example) is too late since their mind has already been polluted with bigoted ideas which are pervasive throughout society. A child should grow up being equally curious about boys and girls. Youth should be free to choose same sex relationships without any pre-conceived notions about what is "normal". When these goals are realized, discrimination against gay, lesbian, bisexual, and transgender people will end.