I don't know. Couldn't it be a kind of evolution?
In the early days, birds were everywhere. Killing a bunch of them in a day may not have required much skill.
If you see 100 birds a day and you're a 10% shooter, that's 10 dead birds.
As bird pops declined, people needed to become better shots to bring home the same bags. So what do they do, they modified their shooting style and went from shooting 10% to shooting 30% or better.
Also, as more and more people took part in competitive shoots, the competition was more intense. To win, you needed an edge.
The best shots stood out from the crowd. These guys may have adapted the less drop, head down style as an edge. As they won, people imitated them.
Just a thought...
Besides, if a lot of drop and a heads up style was an advantage, serious shooters -- Olympic level, pro pigeon shooters, etc -- would be doing it.
OWD
