Then what did the "Intelligent Designer" do, if not create a design?
ID is creationism.
Besides the logic, you can tell it's the same thing because of the people surrounding the movement. The same people who promote Genesis creationism promote ID.
That is the killer point isn't it. People can claim that they reject evolution or promote ID for rational reasons until they are blue in the face; problem is, every single person who does so, without exception, is a convinced religious believer. So even though some of them think that they reject evolution rationally it is just Morton's Demon in operation.