CMake generates Makefiles (and other build system files on other systems). If something doesn't work, you can either fiddle with it without understanding what you're doing, or you can look at the Makefile and see what went wrong...

I prefer to just use plain Makefiles, they're easier to fix and "make correct" than anything else. For me, I guess. make is weird, but more minimal than cmake. (cmake is HUGE. autotools are a lot weirder than make. considering the alternatives, I actually like make...)