I would suspect that there are very few places where image X "really does ... represent the whole idea of" Y. Should we therefore convert Wikipedia into a text-only encyclopaedia?
If you don't want to keep on having this argument, then start a discussion at Talk:Intelligent design & get a WP:CONSENSUS. As long as you don't have such a consensus, I doubt if you'll get the removal to stick.
''TalkStalk''(P)