Out of curiosity, why not use make for something so simple instead of a Shell script?

Because I don't see any value from using it. It's not easier to read or write, it doesn't force you to keep it sane and simple like a bash/cmd script generally would, and it's just another dependency I don't really need. If I take a minimalistic approach to build systems, I prefer to go all the way.

Also, although this is merely a personal quirk that shouldn't persuade anyone else, I've seen enough horrific, unreadable make files to instinctively dislike them by now.

In my mind, shell scripts are simpler. I have no reason to need the extra complexity that make brings.

Also, I do a lot of programming on Windows, where GNU make would be another dependency to install. (Also, in my experience, make is slow on Windows, since they have to emulate fork()). I guess I could use Microsoft nmake, since I assume it's still installed along with Visual Studio, but again, batch files are simpler.

Take a look at this: http://news.dieweltistgarnichtso.net/bin/redo-sh.html

And for GNU tools on Windows, I would heavily recommend MSYS2 these days - having Pacman as the package manager is very nice, and there are already a lot of packages there.

My thoughts are a shell is usually installed by default. Make may not be. This is only a guess. I'm not sure myself.