QM did not go into blind math mode. The way physicists usually do QM is by glossing over a lot of the subtleties of Hilbert spaces and act as if the results from finite dimensional linear algebra work. Concepts physicists have been using for a long time, such as the Dirac delta function and path integrals, only got formalised much later. Many revolutions in QM, such as Feynman diagrams, are very much based on intuition. You can transfer all of that back into formal math, as Dyson did, but Dyson could not have done so without Feynman having invented them first.
Especially in mathematics it is fashionable to write proofs in a style that completely erases the reasoning that lead to the proof. I think that's a pity. So much unwritten knowledge gets lost that way when the originators die. Differential forms, for example, have a beautiful geometric interpretation, but the way they're taught nowadays obscures that completely and makes it seem like they're a formal algebraic tool only. In fact, we're now several generations later, so even some of the instructors may be unaware of that, because their own instructors failed to transfer the original geometric intuition!
Especially in mathematics it is fashionable to write proofs in a style that completely erases the reasoning that lead to the proof. I think that's a pity. So much unwritten knowledge gets lost that way when the originators die. Differential forms, for example, have a beautiful geometric interpretation, but the way they're taught nowadays obscures that completely and makes it seem like they're a formal algebraic tool only. In fact, we're now several generations later, so even some of the instructors may be unaware of that, because their own instructors failed to transfer the original geometric intuition!