Yep I always read about Midway being the turning point of the Pacific War, but Coral Sea is where we finally blunted a Japanese offensive, isn't it? And I think the Japanese had no more successful Pacific offensives after that point. Every following campaign ultimately failed - Midway, Guadalcanal, New Guinea, etc.
Midway was a great US victory and a much more devasting loss to the Japanese material-wise than Coral Sea, but it was the 2nd failed offensive, not the first. Their offensive momentum had been stopped at Coral Sea; that's I why I call that battle the turning point instead of Midway. Not sure if anyone else ever saw it that way (war historians I mean).
Usually I hear Coral Sea characterized as a tactical Japanese victory but a strategic US victory. If that's fair, then Coral Sea was the first US victory in the Pacific War, after which the Japanese won no more significant victories? Wouldn't that fit the definition of "turning point"?
Midway is probably considered the turning point because after that battle, the Japanese stopped thinking offensively.