Sure, these are the kind of concerns engineers raise when you talk to engineers who are right for the job but not worked on OSS before:

* Perceived job security, especially developers with mortgages, families, etc. Going from a core-function role within a company to working on OS apparently feels like less job-security.

* Don't want to move from working in office environment to (probably) working from home.

* Project politics and different working relationships of "peers" - not aligned colleagues for same employer.

* Not considered the most financially lucrative engineering positions in terms of performance bonus or career progression