This is infuriating! I was playing Prime last night and banked some motes right after the "Bank those motes to summon a primeval" line was heard. As soon as I did, I got the medal "Following Instructions" I had never noticed getting that before so don't know if it's new but I started laughing and yelling at the blueberry across the map holding 13 motes, and still fighting.

It's new (it was introduced with Gambit Prime), and it amazes me that it hasn't had a larger effect on behavior.

I think a lot of people learn to just tune out the announcer voice since it's just fluff most of the time. (Shaxxgasm anyone?) I'd love it if the Drifter continued talking to you if you didn't turn in the motes though. He should start saying the kinds of things the rest of your team is thinking like "What are you doing!? Get to the bank and summon that Primeval now!" or "You can't collect any more motes! Get to the bank!" or "Your ghost must have scrambled your brains the last time he revived you. Deposit those motes!".

The problem is that Bungie doesn’t bother to teach players how Gambit works.

I have been that person before, because I have a bounty for banking motes, and I just need those few extras to finish it and not have to play another match. It’s not always player incompetence, it’s the fact that Destiny is designed so that winning isn’t the primary motivator for players in competitive activities. Bounties and Triumphs and some quests actively encourage behavior that isn’t necessarily what’s best for winning matches. Trying to win games of Crucible or Gambit with randoms who might not even be trying to win is an exercise in frustration. I’m off not trying to win when I play. I’m in the middle of the Malfeasance quest. That’s what I’m playing for when I solo queue into Gambit—winning means nothing to me until I get to the step that requires wins.

Okay, I get all that... but in this case, none of that applies. In standard Gambit (which is what he was playing), 15 motes is the most you can hold. When you collect 15 motes, a tone sounds, a large message appears on-screen telling you that you're holding max motes, and if you miss all that, it's not really Bungie's fault for not being more clear.

He can't pick up any more motes, and the game has told him (more than once) to get his ass to the bank and deposit what he's got. He can't complete more bounties by running to the other side of the map - all he can do is lose the 15 motes he has.