If some group doesn't want a gay scout leader, they should just accept it and move on to another troop. Why should a persons involvement in scouting be related to their approval of a homosexual lifestyle?
Because you are the one being offended
Same applied to troops accepting "negroes" and people not wanting their sons in a troop led by a negro
Society changes
Race and sexual orientation are not the same, no matter how much your side tries to make it so.
Society can change, but you forcing it to change by being assholes via the government is wrong, and that you don't see it is sad.