You're a medic. You've got a nice skill that needs a lot of supply pips (the revive nade?), so you want to keep your supply bar pretty filled up in case you need that skill.
Then, a teammate spends all his pips in armoring and buffing the team, for example, and starts asking you for your supply pips while you insist you're saving them for something else.
Do you think this could lead to "bad feelings" and loss of team coherence?