As stated elsewhere, this helps establish the credibility of the selection process in the eyes of the French fiscal administration, which, ultimately, is the biggest funder of the FDL (through various tax incentives).

Moreover, as it is a voluntary function, no one is harmed financially by this constraint.

NumFOCUS has a huge overhead for directors and staff ($605,615.79 in 2020). This is not looked upon kindly by OSS authors who are doing the work and get much less (or nothing!).

If this foundation does not have such an overhead and will never create cozy director posts, cozy diversity officer posts etc., then this is a huge credibility boost and I'd mention it on the website (with the explicit promise!).

But then the foundation has to stick with it and not stealthily sneak in CoCs and people after a while.