I hate CMake. I hate autotools, too. But, if there's going to be a replacement for autotools, it's gotta be better than CMake. At least autotools is standard on every Linux/UNIX system these days. CMake is just another build dependency for very little gain.
Don't use them. Makefiles are fine. So far i haven't seen the need for configure magic. On the other hand, i do not work on software, which needs to compile on archaic AIX systems.
That's probably fine as long as you're just compiling .c to .o. I suspect it breaks down in the face of anything more complex. For instance, I've got a problem right now where I need to use objcopy to turn arbitrary binaries into .o files, and that requires knowledge about the toolchain on the user's machine which, as far as I can tell, can only be gathered by compiling a throwaway file and sniffing its output with objdump. That's exactly the sort of task which autotools is good at, but I'm desperately trying to find a different way to get at the information so I don't have to introduce autotools to what is otherwise an already... erm... interesting build chain.
Whoah! Hold on, now. autotools (and CMake) exists for a reason. They, in many cases make your life easier than maintaining makefiles. I do think make is much easier to work with (with some warts) than autotools, and it's certainly more comprehensible, since it's so much smaller and contains far fewer bits of magic. But, to just throw out everything autotools were designed to deal with doesn't make sense.
Sure, if your build is simple, make works fine. But, the projects I've worked on where autotools was used, simply using make would have been a horrible experience. And, in most cases, the projects started out using make by itself and then moved to using autotools when the number of platform specific makefiles became too big to maintain.
Custom-made build systems tend to break conventions that are useful to packagers (destdir) or home-directory installs (prefix) or developers (ccache, though your example isn't guilty of the last one). I'd rather build something that handles all this and integrates well everywhere than see variations that need custom patching.