GNU make isn't part of the base system for the BSDs, but I've found that it is often installed on BSD systems anyways (as gmake), due to much software having a

GNU make isn't part of the base system for the BSDs, but I've found that it is often installed on BSD systems anyways (as gmake), due to much software having a build dependency by using Makefiles with GNUisms. If your project is targeting a generic POSIX environment with build tools available and you want the portability, I can see why you might go with the lowest common denominator. For a lot of projects though, there are additional non-base dependencies (e.g. a python interpreter), and having a build dependency on GNU make is usually acceptable if you're using the extra features (e.g. % matching is a big convenience).