There are plenty of homosexual "churches" who would be more than willing to flood in to pervert this formerly honorable organization at light speed by sponsoring a troop of its like-minded congregants. And once instituted, what normal boy would want to belong?
Concentrating the same perverted world view universally among themselves, these monolithic scouting units will reinforce their radical activism. They will rewrite and adopt their own rules, which will be NOTHING like anything the upper level administration intended. Scout troops operate fairly autonomously, and if no one in the troop reports violations, they are free to operate as they want, adopting uniforms to their own specifications (imagine rainbow neckerchiefs) and standards of conduct acceptable to themselves.
These homosexual troops will, inadvertently, be thrown together with normal boy scout units in council-wide camping events, national jamborees, and other multi-unit scouting events. Most organized scout camps have no physical divisions between campsites and are often directly contiguous to each other. The radicalized and newly emboldened homosexual scout units will have a field day. And with the new PC rules, no one will be able to do much about it.