According to one article I read about it, it's because the wide-angle photography is where one can actually see what is going on and get a feel for the strategy and formations. Most of the TV footage is carefully composited to give the viewers what the networks think they want: focus on the ball. But there are many facets of a given play one doesn't see from those angles, that are more obvious from the wide-angle shots.
I would think that a scout would spend more time focusing on individual players than overall schemes, though, which leads me to believe that the available footage would suffice for most of what an aspiring scout would be trying to do. At least, that's how the scouts I've read about got established: watching footage and, of course, attending games whenever possible. It's obviously a lot easier to attend college games than NFL games, though.