In my opinion anyone who is really serious about programming should pick up a bit of machine code experience
That's what's fun about Java. The JVM is a stack-based architecture down on the bytecode level which can give beginners an idea of what assembly development is like, without getting into the hair-pulling extreme of having to deal with (or debug) direct memory access and segments and all of that. A single method can be heavily modified or even completely rewritten without affecting anything else in the class, where as in standard machine code you'd have to slip in a jump somewhere and execute code elsewhere to avoid breaking offsets. The JVM is also very forgiving about the stack, because each method uses its own stack frame, where as in assembly, forgetting to restore the stack could be a death sentence for the application.
Coremods are generally seen as a bad thing due to issues that they can introduce, but the irony is that the experience modders gained from it may very well help them in being introduced to x86 assembly to mod this new version.