Yes Finn it does happen, and make sense, or at least did. But perhaps also what you are seeing is partly an age related phenomena, or geographic.
In my school year of 126 students, there were no out kids. Not one. At least 6 have come out in the 20 years since. The idea of being out then, would have been crazy. You would have painted a big neon sign on yourself.
Now, I talk to my nieces and nephews, and its just normal that some of their classmates are gay. It's just another fact about them, like what football team they support. This is however in a big city and affluent schools.
So it would be a natural for someone of my age perhaps to write that sort of scenario, but maybe as time goes on it will become less an assumption you can make.
Your question gives me hope though, that we can get to where we should be, and perhaps in some places we are getting there.
My feeling always had been, that this crap ends when people start asking themselves why on earth would you have a problem with someone being gay, rather than why wouldn't you. When we actually sit down and say, it does not make sense. So perhaps your question is a sign on the road to where I hope we are going, to the point where homophobia seems as sensible as phrenology.