Articles like this one are more likely to drive people away from make(1) than teach them to appreciate it.
This Makefile is anything but simple. It uses advanced features that are meant for complicated situations, just to create a few symlinks. The same symlinks, every time. And if you introduce a new dotfile to the repo, you have to update the Makefile too.
It also makes no use of the main feature of make(1) - to track files for changes, and update them.
For demonstration, here is the same functionality, in sh(1):
files=$(find files -type f | sed s=^files/==)
echo "$files" | sed s=[^/]*\$== | sort -u | { cd; xargs mkdir -p; }
echo "$files" | xargs -I{} -n1 ln -sf $PWD/files/{} ~/{}