I interacted a bit with the OWASP community a few years ago, and it seemed to me the O on OWASP is not really there. It feels like the community is made of a few guys, the typical stereotype pentester: a bit arrogant, and difficult to communicate with when you have different views.

Sorry for the negative post, but there are no comments on this story and I felt like I needed to say this.

For what it's worth your view is contrary to mine: I've attended quite a few local OWASP chapter meetings and volunteered at OWASP AppSec. I've found it's a pretty diverse set of DEFENDERS, not so much the pentesters. Also found some of the best non-vendor/sales pitch talks to help raise knowledge and awareness in the appsec/ infosec community. I will admit they don't drop cutting edge knowledge or zero-day type stuff. They are a pragmatic group trying to make things better. I think this is a hugely valuable effort.

The linked manual is available for free in multiple formats, and the README specified multiple ways for potential contributors to become involved. How would you suggest it be made more open?

I think he was referring to the process used to create the material.