I'd like to stress a passage which made me think quite a bit:
We have never pressed contributors to endorse the GNU Project philosophy, or any other philosophical views, because people are welcome to contribute to GNU regardless of their views. To change that -- to impose such requirements -- would be radical, gratuitous, and divisive,
What holds the project together is indeed something else. One can debate what qualifies as "views" and whether radical changes are necessary, but personally I appreciate being reminded to be careful about this point.
I've tried to think of analogues outside the usual communities we usually have in mind. In my home town there is a refectory run by Franciscans: I may be mistaken, but if you volunteer there you're not even asked whether you're a Catholic, let alone asked to join functions if you don't want. I understand one may consider that a more menial task, less likely to be influenced by philosophical thoughts than what one might code in their software, but it's just a comparison, not a model.