Comment by AnthonyMouse

That theory assumes you can train >10,000 new air traffic controllers all at once in 1982 but then can't train their replacements over a period of ten years as they retire.

For that to be the case there would have to be some more proximate problem compromising the ability to replace air traffic controllers at the rate it was possible to in the 1980s. Like this: https://news.ycombinator.com/item?id=42939941