I was thinking about the carrier points too. The problem is that if I give points by staying on the carrier, people would abuse the system and just take turns infinitely to level up. You could use 1 game to level up to rank 31 with enough patience
What I was thinking instead is to add/remove points to different teams. Meaning, when your team mate lands on a carrier, it begins adding points to every one on your team and removing from the enemy. And viceversa.
So the enemy has motivation to get you killed and also to capture carrier.