I'd argue that the middle ground, i.e. aerobic threshold pace, has been far from neglected. Aside from easy running, it is the only aerobic work that most American distance runners fit into their schedule. I can count on one hand the number of guys I've trained with that do strict LT work. Everyone else does the MP + a few seconds per mile. Usually starting slower and finishing faster. If you go up to any college/post college runner and ask them to describe a tempo run, it'll be what I described above. This isn't new, I've read Malmo descibe tempo runs in much the same style. My point is that if everyone is doing this aerobic threshold work as their primary means of aerobic training, and we as a country are way behind the world in the aerobic events, then something is wrong.
I believe that my generation was taught the wrong way to train. We were protected from high mileage, always quality over quantity, limited racing, no training on asphalt, intense intervals, and light tempo runs. The results was the Great Depression of American Distance Running. Now I'm doing everything ass backwards and its working. 140 a week, 7 minute pace easy days, lots of races, running on the roads daily, hardly any intervals, and tough LT and MP work. It all comes out of Jack's training.
How's that for a tangent! Tempo runs to the great depression. Too much coffee, another thing I was supposed to avoid.