> I think what he means is that their Makefiles effectively start having a common API across projects, by having similar target names.

> No need to use "all" if you put the default target first (see `default` subsection in the post).

That's obviously the reason they're doing that, but it's an odd decision. Especially since "all" is a common name for a Makefile target and .DEFAULT_GOAL can be used to override the "first target" convention of Makefiles.

    firsttarget: mysource.txt
        cp $< $@

    .DEFAULT_GOAL=all  # no need to put it first
    .PHONY: all
    all: firsttarget secondtarget

    secondtarget:
        touch $@