Commendations were not put in so people would work harder in the dungeons. They were created to get the community to communicate with each other. Most people I know still use them for such. It's entirely possible that if the run was completely silent, that the others didn't bother commending because they found the run boring. Try talking to people, giving advice. I've had past runs where I screwed up and got people killed and still managed to get comms because I was friendly. Other runs, where I didn't want to talk, I got maybe 1 or none. It all depends. I never expect a comm though.