It's just a coincidence
But hunters with military training and map reading skills have been using topo maps, in one form or other, for decades.
Did a lot of solo hunting, as some of my aquaintances had no idea how to use a compass and topo map and not get lost.
Spent many a hunt on public and private land as if it were my own private preserve. It's getting easier with the computer maps and gps and even for the untrained. But I'm seeing a lot less of something. And that is staying fit, as more hunters, and people in general, are gaining a lot of excess body weight. It's one thing to know where it is on a map. Another thing to be fit to hike in and out, with a tree stand on the back.