I was a comic book kid too, but I'm the opposite, I love the MCU. I mean, it's fading a bit now but man, what an amazing thing they did. Building a story line across 30 movies. Not 3 movies, not 6 movies. Not minor movies. 30 blockbuster movies.
Frankly, I think the whining from some of the Hollywood folks is weak sauce. Don't tell me Robert Downey Jr didn't blow everyone away with his Tony Stark. That's an amazing portrayal of the character. Funny, charismatic, believable... I don't buy that the actors disappear.
I saw Quentin Tarantino say that it used to be, you see an actor give a great performance in a big movie and then fans watch other movies with that actor to see him/her again, and that doesn't happen anymore because of Marvel. Again, BS. I've seen a bunch of fairly average movies because Jeremy Renner, Scarlet Johansen or Chris Evans were in them.
I remember Ricky Gervais picking on Marvel movies at the Oscars saying they're more like amusement park rides and that the Irishman was a 'real movie.' The Irishman was great, and yeah the Marvel movies are tons of action and effects but so was Avatar, so was the Abyss, so was Close Encounters, so was Star Wars... Imagine if they didn't make Empire because Star Wars was too much fun.
I don't know. To me, the complaints come off as jealousy mixed with old fart.