Yes, I agree entirely.
Is there a way I can say both that the invasion was stupid AND that it could (not should!) have worked out ok afterwards if the US had a plan?
I think that it is worth noting all the things that went wrong, not just the stupidity of the invasion itself.
No, the real problem was invading a country that posed no threat to us. That was the real crime. The power vacuum could not have happened without that illegal invasion.