A lot of the time I see these build systems try to solve a few issues:

1. Dependency handling

2. Single script for multiple platforms

3. Easy for a new user to just "run"

But I have yet to find a build system (for C/C++) that solves all these issues better than simply having a few scripts.

I use just a build.batch, linux_build.sh and osx_build.sh usually and I have never had problems.

A new user can just download those scripts, and as long as they haven't tampered with file/library locations it just works.

If people like their build systems - fine by me - but I just think they are unnecessarily complex a lot of the time. Granted I don't have a huge project with 100's of dependencies, but even then, those dependencies don't come all at once.