I think that if history is going to judge George W. Bush negatively with regards to Iraq, it’s going to be his idea of having a democratic Iraqi government. Muslims do not understand democracy, and the resulting Shiite government was pro-Iran, while not being particularly fond of America. I would have thought that a secular autocrat (ideally Kurdish, but that may not have been workable) who was pro-America would have been a better choice; any attempts to Islamify the government would have been quickly and mercilessly squashed, and the government would remain anti-Iran and anti-Syria.
Despite George W Bush overestimating the competence of the Iraqis, it’s better than deliberately encouraging both ISIS and Iran to reduce American influence in the Middle East, as Hussein Soetoro has done.
I think you've hit the nail on the head.
Plus, IMO, these countries have been in some form of war for millennia, so for us to expect them to change overnight or in ten years is not conducive to the solution.