That's really being generous. Turkey and Qatar directly financed ISIS and facilitated movements of terrorists. People were recruited in countries like Tunisia through mosques, some of them very far from being a committed to the religion. The jackpot was money to be paid, and whatever "pussy" your hands can get once you are in Syria.
The US turned a blind eye because ISIS was fighting a regime they wanted to change. They could have pressured Turkey and Qatar to stop; and they would oblige. But everything has a cost I guess.
While some of this may have happened, both Turkey and Qatar's assistance is dispute, reports say 70% of members in Syria were Syrian and 90% of members in Iraq were Iraqi. The leadership has been full of former members of the Ba'ath army and intelligence agencies who lost their jobs during De-Ba'athification.
Stopping the help provided by outside countries may have weakened the movement, but not prevented it.
The US finances many terrorist groups ourselves, so I'm not sure what your point is—nations are happy to take advantage of new powers regardless of how it conflicts with their propaganda. I don't know how you could look at the invasion of Iraq and come away with the conclusion that ISIS is either surprising or could have formed without our help.
The US turned a blind eye because ISIS was fighting a regime they wanted to change. They could have pressured Turkey and Qatar to stop; and they would oblige. But everything has a cost I guess.