So you are saying it is OK for someone to make a big deal out of being homosexual as a candidate, strongly advocate abortion as a means of birth control, advocate condom distribution in school since the little animals can't control themselves, etc, etc, etc, but advocating self control over sexual urges is not?
There was a time not all that long ago when biblical morality was generally taught or supported in public schools. The Bible was used and revered. We did not have the level of violence in schools then as we do now. Making an exclusive cause-effect claim there is probably not valid but the move from a Christian moral paradigm to a secular one in public schools does very much parallel the rise in a whole host of social ills in HS's to include shootings.
I saw a survey once of HS teachers in the 1950's compared to modern teachers. The biggest concerns back then were things like talking without permission, being late, failing to do homework, chewing gum, etc. Now it is weapons in school, gangs, drug trafficking, teen pregnancy, etc.