Ah, but that was the crux of the case. They were arguing that their alcoholism was a status, like homosexuality, and that they were illegally being punished for it. That's why I felt comfortable using the same analysis here.
Unlike being drunk in public,
Like I said, the distinctions are tough to draw sometimes... you'll notice that your comparison is off. You compare an status with a condition. Properly put, you should have typed, "being a drunk in public". (That is a status, like being a homosexual.) There are also no laws against being a drunkard and being out in public while they are sober.
being a gay person in public is not a crime.
But that is not what is being debated here. Nobody has said that gay potential Scout Leaders should be imprisoned or fined, only that the private organization has the right to exclude that group. Consider the nasty problems that arise if/when a gay Leader improperly touches a child, and the BSA is sued for putting the children in harm's way. This is the exact liability that they are attempting to avoid. If, by law, you force the BSA to take those Leaders, you can't hold the BSA liable for their acts, because their only other option is to disband entirely... and that changes yet another entire area of jurisprudence.
A hypothetical: Men's clubs who refused to hire women are forced to do so via lawsuit. A member sexually harasses (or worse) the female employees. Should the Club now be free of liability because they were forced to hire the females? Are they no longer responsible for their safety? Of course not! Clubs, employers, and private citizens have responsibility to do so because they have the power to do so. If you take away their power to protect their charges, you also remove their responsibility.
You may not like the choices that others make, but if you force them to make the choices you want, you also take away their freedom, their responsibility, and the consequences for their actions. Not a good exchange by any measure... especially because that power will eventually affect you and your choices in a similar fashion. (Here's an example: can the majority now tell gays who they can and can't associate with in their private associations and clubs, and have the force of law behind them? Shall we say a limit of one gay man per room? No? Well then, why can gays tell the BSA who they can choose to be Leaders? Heh-heh, I can't wait to see the first KKK meeting where they are required to admit Black Panther members. I hope there are enough federal agents on sight to stop THAT skirmish!)