If someone is truely a fan, they wouldn't worry about what a players cap figure is.
OK, you just got two other responses on this so don't take this as a dog pile, but with a hard cap there are really two ends to the worries (1) one paying too much for a player that underperforms (the worry seeing that Carr has not yet performed at top 10 level but will soon get paid that way) and (2) paying a player so much that the team suffers more from the cap than it does from his talent (Peyton Manning).
If a QB is just going to be a yeoman game manager then he needs to get less money to put players around him that make them look better. If a QB is going to suck up 25% of the team's cap, they better be able to get scrubs to score 35 pts per game or they aren't worth it. Hopefully, Carr's character and hard work turns into on field performance justifying the money he is set to earn.