I agree, but I can still think of good reasons why Bolton is important. The Iran deal was a success for Obama against a lot of opposition. That opposition has not disappeared. For instance Trump remarked early on how anti-Iran the Pentagon was. Bolton played his role in cancelling the deal, a step which others would have been too cautious to take. Without him the situation would probably not be what it is today. But removing Bolton does not suddenly make it achievable to reinstate the deal.
With Bolton the conflict with iran could escalate to war. Trump does not want that. The Pentagon does not want that. I don’t see him having problems with draconian sanctions. He’ll want to negotiate with Iran to achieve a level of sanctions which is a little less than what would result in annoying backlash. It’s Iran’s job to convince him that this won’t work.
Bolton sabotages deals and poisons relations. IF someone is interested in making a deal, whether it be Afghanistan or North Korea, then it is good not to have Bolton around. Or his minions , for instance Kupperman.