No one's saying that everyone should become gay, even if it were possible.
They are promoting it as something cool and normal, which makes a lot of teenagers experiment with homosexuality who would otherwise not even have thought of the idea. As a consequences, many people unnecessarilly go through the more horrible identity crises for no reason whatsoever.
Heh. Wow, of all my involvement in gay advocacy groups, and gay-straight alliances, and my gay friends and myself, I've never heard any of us describe it as "cool" or "normal". (Actually, with regards to normal, actually I have heard it, though in the "natural variation" sense rather than statistically.) Much like I wouldn't describe being autistic as "normal" or any more "cool" than being NT - though it's a natural variation that should be respected for those with it and not be looked at as defective.
Also, you speak of rational arguments, and facts, in discourse, so surely you should be able to pony up some facts to the effect of:
a lot of teenagers experiment with homosexuality who would otherwise not even have thought of the idea.
Some people are on the verge of bisexual when younger, but then realize that in fact they're straight, or realize that they're gay, and some realize that they are in fact bisexual. The only difference between these identity crises and what would be there if it weren't for gay advocacy, is that those who were unsure would feel even more pressure to "aim for straight" regardless of where they are on the sexuality spectrum, as they wouldn't have a supportive voice for them.
The problem is the statement I italicized, which is NOT a "simple fact". Most research indicates the opposite.
In every single human civilisation, the marriage between a man and a woman has been the norm. Sometimes it's more men for one woman and sometimes it's the other way around, but homosexual relationships have always and everywhere been a deviance.
No one contests that heterosexual relationships are the statistical norm. And something being considered a deviance by a society doesn't mean that it's a "simple fact" - for instance autistics are considered deviant, not so much morally but in terms of neurological wiring - still considered defective by a lot of people, but that doesn't make it fact.
For instance, you even mentioned in an example about how people weren't lining up in droves to defend Galileo - his ideas about the earth and the sun were not at all respected by a lot of people. Just because a lot of people don't support something doesn't mean that it's inherently wrong, whether it's an idea about the solar system or an idea about the rightness or wrongness of homosexuality.
Deviance is a negative value judgment of a difference that is in the minority.
My point was merely to illustrate that something being offensive to someone shouldn't be a criterium for that statement being said or not.
If what I'm saying is offensive to you, it's probably because you know it is true.
Those statements don't look very much alike in meaning. Perhaps you could enlighten us?