The committee is made up of individuals from each of the member organizations who generally have other responsibilities in their company than just OpenMP. Each topic for a new release is suggested by someone, prioritized, and voted on for possible inclusion. Once a candidate list is drawn up, someone has to chair a sub-committee, lead the discussions, and submit a proposal for addition to the spec. This proposal is then reviewed by the full committee and if it passes a vote of the member organizations, added to the spec. Because of the amount of work required, not a lot of new features can be added for any new version of the spec.
So while it might seem like it should be trivial to add a new version of a base language, it takes a lot of work trying to look at all the new features of a language, trying to figure out how best to support them within OpenMP, and going through the process. Fortran 2003 was looked at and added this time - but not all of the new features are supported. This is a continuing process.
Another thing to be said though, is that a lot of the member organizations are computer manufacturers and so customer feedback is very important. If there is some feature that users say they want, it has a better chance of being higher on the priority list and making it through the process. That said, what is it that you were expecting to see support for?