> You got any idea why people hate the concept of nested functions in C?

It breaks the model of c mapping to the hardware.

Functions in C are just labels you jump to. Assuming you want to capture values from the environment you're defining the function in, you have to implement some sort of function struct that is callable, and it probably won't work with any shared libraries on your system. Also it would be slightly slower, and C programmers tend to not be willing to make that tradeoff