Dealing with unnecessary build and packaging complications, often dictated by legacy constraints, is a distraction for a systems programmer and does nothing for the quality of the software itself.
I have contributed to projects where I am neither motivated or knowledgeable.Sometimes its enough to be annoyed by a bug or confusing behaviour.
You are potentially missing out on a lot of talented systems programmers who are not willing or able to put up with terrible build and packaging infra and therefore stick to another domain.
As for motivation, you are also missing out on anyone who has a small contribution to make but isn’t willing to dedicate hours trawling through Makefiles. That doesn’t seem good either?
I don't have anything valuable to add, hopefully someone else might.