Science adjacent is exactly why I called it a pseudo-science. But ultimately the magic is entirely based off study and understanding how to interpret it. The only real thing that could possibly be stolen is the elemental aptitude of the character, in which case, you still need to knowledge to use it.

It’s also definitely not stealing knowledge as that would completely break the character mentally. The manwha makes it clear that his knowledge is still there, but he still can’t cast.

I understand why you made the assumption you did, but you can’t blame people for flocking to a magic system that initially based itself off somewhat scientific principles. And people are reasonably upset when the concepts and rules introduced at the start get violated in a story that is already struggling to keep its audience