The “failure” of the CentOS community is really related to the nature of the distro. As they aimed to be a fully compatible clone of RHEL, there’s not much you can allow in terms of community contribution to packages, etc,. Those kind of restrictions don’t lend themselves well to forming a vibrant group of contributors.
The main area that was lacking are the other resources, like wiki, forums, and other docs. That’s one area where criticism is warranted. I always wince when I have to go to the Arch wiki to figure out how to set something up in CentOS.