There's a big difference between researching a topic to a standard good enough for 'popular rocket science' and 'understanding the maths well enough to work in the field'.
OTOH at the point that you're EDM-drilling thousands of micron-scale holes in your combustion chamber for film cooling, you may start to need practical experience with different things.
Yes, straight educators are not generally considered divulgadores; if someone is teaching a university class on linear algebra, that doesn't make them a divulgador. Unfortunately https://dle.rae.es/divulgar is not very helpful, but https://www.etymonline.com/word/divulge gives a bit of the flavor.