King is a title, Queen is a title. They havent voted a boy Queen yet cause none have come out.
Titles are supposed to have meanings or purposes though. The purpose of these titles is what determines whether or not this is great, nice, stupid etc...
If its supposed to be about simply the most popular boy and girl, then voting girls for king or boys for queen is simply silly and beats the purpose. What if a year came and the two most popular people were two boys or two girls who weren't actually homosexual, do you still crown them anyway?
If no, then its obviously not just about the two most popular people in general, but either specifically the most popular boy and the most popular girl, or the most popular couple in general. Which one of those two options determines to me whether or not this event warrants any 'opposition' or anger.