John Woo slam MCU movies.

1) That is not a slam. A slam would be if he were to say "They are junk, and those thinking they are anything else are morons." He is not saying they are bad movies or badly made at that(In the Deadline article which contains more information about said interview he says that he appreciates that they entertain and make profit) but he has concern for youth who may think big spectacle features are the beginning and the end of the cinematic marketplace. This concern is nothing new, and has always been around in culture by experience artists even before the motion picture was created, when something extremely popular and commercially successful with youth the older folk express concern that they may avoid seeking out something older or even less commercial that may be of better quality.

and

2) In the same interview he admits that he recounts a personal story with Stan Lee and says that he had to reject the offer to direct a superhero movie because "I'm not a sci-fi guy - I don't think I could make a good one. There's so much imagination...I don't think I can reach that level."

I also see that you've not mentioned that Roland Emmerich isn't too big on Marvel movies, either, odd since you seem to cling on just anybody's opinion on Disney-Marvel which isn't 100% in their favor.