These petro states suffer from the curse of natural resources combined with leadership that is too busy feasting off of the intermittent boom cycle to prepare their people constructively for the bust that comes later. So you have entire countries that are basically dependent on the oil handout, and in bad times, have little industry to fall back on and wait for the next rise (or foment civil unrest).
Some of the leaders do know that they can't live on oil forever, so you see some sovereign wealth funds investing in things that their people can learn and use to build their society more resiliently. But in general the improvements are not very deep -- the money comes too easily and people get used to state intervention and not having to work.
It's a problem.