Customization for big enterprises is actually a viable business model, only if it generates as much money as the company sustains and can continue to expand?
Yes, it is only a viable business model in the end if it generates enugh revenues to cover materials and labour, like every business on planet Earth.
As a contributor, I never particularly cared about permissions if I participate in a project with a few patches. It becomes useful when you are diagnosing a CI problem, etc. and you need to push a lot of tweaks to discover where the bug is located.
More generally, treat contributors like you want to be treated. Try to be responsive, compassionate, guide them through the process of having a PR merged, be ready to fix a minor mess or two, congratulate them on a job well done.
Open development is as much a story of people as a story of code.