Do you think the Bushes were against Saddam because Saddam was "killing his own people" ??
No, under Saddam, Iraq was a moderately progressive Muslim-majority country. What the White House desires is religion-obsessed reactionary societies which are essentially slaves of White House and NATO.
This is the same case with Libya and Syria.
Bush Sr went after Saddam because he crossed the limits of behavior and became a regional hegemon.
I do not know about the motivations of Bush Jr/Cheney/Rumsfeld crowd. They violated every principle of internal behavior to depose Saddam. It is almost like they wanted to create chaos.
The current state in Iraq is moderately progressive by standards of the Islamic world. A lot of other pro-American states like Jordan, Morocco fit the bill.
The reactionary societies have too much money