As a producer, I have better things to do with my time than trying to figure out which regular expressions to run over snippets of Makefiles held in a giant string to make MM do what I need it to do in a way that might possibly work across platforms.

Sometimes I have to read the source code of Module::Build to make it do what I want. That's fine. I've read part of the source code to MakeMaker (to write tests for parts of it). I have no desire to do that ever again.

Module::Build does what I need it to do and almost always gets out of my way. I don't have to spend time thinking about it. That makes producing code -- not customzing build systems -- more fun and it makes me more productive.

I do have my Build.PL files create traditional Makefile.PL files, but I won't mourn MakeMaker when it finally goes away.