The issue for Indiana isn't whether the max-contract offered Hibbert is a good value or not. It's whether they can have a financially solvent team if they match. The problem is that while this year they are in decent shape, next year Dave West, Tyler Hansbrough and Darren Collison will all be up for new contracts as well. The year after that Paul George will need to be re-signed.
If they commit to a max on Hibbert they will have $33,000,000 tied up in Granger, Hill and Hibbert. Assuming West is a key part of the team they will need to offer at least as much to him as Hibbert is making. That gives them 3 near-max players and a $6 million player on the roster before they've even filled in around them. If they believe Granger, Hibbert, West and Hill are the equivalent to Wade, Bosh, James and Miller then this wouldn't be a bad situation, but I don't know anybody that would posit that. Throw in Collison or an equivalent point guard and they're pressing against the salary cap with a team that probably is at best a 2nd round playoff team. If they want to keep Hansbrough then they're over the cap. The year after if they resign George they would be hitting the luxury tax.
They also would have no flexibility to improve the team except through trades and very few teams are going to trade for a $14 million Granger or a $12+ million West.
So the question they face is do they see this core as good enough to keep their fans happy, because if they resign Hibbert they aren't going to be able to get much better. The only development they will see is getting lucky in the late draft, internal team development or trades.
(Note: These number's are guesses based on what I see on storytellers site)