It's probably half and half. Like half of those sprouts haven't yet realized how to give commendations or why. The other half is the sprouts having their own ideas about who should get their comm. A lot of people who are stuck on getting or giving commendations usually see people being really helpful as, "This guy is just doing it for the comms, but he's not so great. I will comm someone else!"

Weird psychology going on.

Another thing is like, people only comm based on the skill they themself can perceive. Like you might carry a run on tank by being really good and using your heals and group mit to keep people up as the healers die or your invuln to buy just enough time for a healer LB3 or something... but the players just see, oh the healer LB3 saved us all! Everyone comms the healer.

There's only been one time when I got every comm from an 8 man group, and that was on my LP alt when I did Tsukuyomi for story. I clutched out a win with Living Dead, killing her with 4 seconds left on Walking Dead. This was after two wipes, so everyone wanted to be done. There was much rejoicing.

Personally I usually feel pretty good even getting one or two comms, because it means someone noticed me. I play a lot, so it adds up, and I feel like I usually get noticed. Not a lot of runs happen where I get none, even on DPS, so I can't really complain.