I'm fairly sure it isn't because he didn't make the MVP incentive clause in his contract, if he even has one. Shaq undoubtedly had a great year, but the process goes way beyond that vague measurement into one that is even more imprecise.
Value comes in all different shapes and sizes and is certainly particular to all different sports.
This year, I voted for Allen Iverson for MVP, Shaq second and Tim Duncan third. I'd like to think I understand value. In other words, it's clear to me that Iverson played the biggest part in how well his team did this year. The problem is trying to understand how other people define value. Last year, I was one of the majority in the almost-unanimous MVP decision for Shaq.