Make is declarative. You tell it how to make an A from a B and a B from a C or a D and it then works out that it needs to do "CBA" or "DBA" depending on wheth

Make is declarative. You tell it how to make an A from a B and a B from a C or a D and it then works out that it needs to do "CBA" or "DBA" depending on whether it finds a D or a C in the filesystem. The more possible variations you have to cater for the worse build scripts get. If you try not to redo work that you did 5 minutes ago that's still valid then build scripts become even more complicated whereas the makefile doesn't change at all. Other tools do declarative even more than make does but as they get easier to understand they tend to lose abilities.