The thing with meditation and repetitive physical practicing can easily have something like chi that descibes the feeling of getting thigs right in a way that some people take literally magic. Like how focusing on moving something can feel effortless because practice has made it a whole body motion. Or how thinking about punching past something makes it easier to hit it harder because your brain is less likely to subconciously pull back on impact.
The mental part of martial arts is like medidation. There are real world benefits, both mental and physical, and having a long history that intertwines mysticism means a lot of people are going to start to believe their own hype.
Well, yeah. If you do the work as your primary job you will have more time to do the work than if you only do it in your spare time.