I disagree. On King, I think I can comfortably get the GL every time if I want to, without feeling like I really had to sacrifice much to get it, unless I was set on getting the Hanging Gardens or Petra, because they require teching too far in the other direction.
If you have Philosophy unlocked by the time the GL is built then it really is very strong in the early game, so I often go for it on King unless I'm specifically aiming to rush something else.