Another gobshite here, the only thing that shuts me up is a lack of fitness and a pace that sees me unable to 'multitask'.
I'm never quite sure about going on a group/organised event ride and then riding on your own in silence. If all you want to do is tick a check box for having done a certain distance then you can do that on your own anyway. Though I fall into the category of people that wouldn't bother getting a card stamped and wouldn't collect a certificate. The other aspect is distance/time perspective is a funny old thing, you can mentally make them stretch and contract but having a natter works better than anything else.
Re the OP and an age thing, that's just people, territorial, tribal, awkward, insular - join any club and you'll find the same sort of thing - some golf clubs I've played at have cracked me up