I suppose I was wrong about the author's reasoning, but I still think my description applies to many people.
Personally, I think both camps have their problems. Academic people can be quite annoying when they talk about something like they know everything about it just because they've read some paper about it. On the other hand programmers knowing only one language and framework are equally limited in their view.
I feel the author is saying that knowledge should be tested against reality. The test should not be a quiz administered in a closed classroom. Knowledge should lead to outcomes in the real world. It should be hardened against the real world.
It sounds like the author unfortunately hit a place that requires more classes and teaching before getting to the point where research becomes the full time 100% job. It also sounds like the author was trying to take several courses and be a teaching assistant at the same time. That's a lot of work for anyone, even people who are good at multi-tasking.