My guess for your musing

They trust your capability, but need the Sr. Director to be somewhat responsible. So he takes on the challenge to figure out how to work with you over time.

Personally, I suspect that you work well with certain type of people (likely your kind of people) and have a hard time working with other types of people. So it could be a good opportunity for you to see how other people ticks:) I would take the opportunity positively.