Guard are pretty into it, as much at least as marines. Even Custodes are more into it than they were at 30k, though more in a philosopher way than a zealot's.
Sisters of battle got zero scientific knowledge beside some medicine.
Telling them to invent advanced stufd would be trying to get Jack the squad medic to redo Manhattan project.
But the Admech is a weird combo of both. Why they do prefer STC, when pressed, they will do the dirty research.
I think it is not that illogical. If you got old technology, that was propably invented with super AIs's help, that is barely understood and can be very destructive, you mess around it with caution if you must.
Over time that becomes dogma.
This would also explain the cybernetic fascination. If you can't have AI that you need to do this super hard science with, you become the computer yourself.
So the Mechanicus make for good engineers and scientists, but the nature of their environment, lot of unstable, sometimes irreplacable stuff that is barely understood, and design flaws being a doorway to the Warp, is really something that you don't want if you need to innovate.