There are some purists that refuse to accept any alterations to the gospel according to their comic book creators. I get it but what works in one medium may not translate to a different medium. A good example would be the first Fantastic Four movie where the origin story from the comic was changed to include Victor von Doom with the rest of the gang to be bombarded with cosmic rays which endowed them with superpowers though, Doom’s powers are not clear or as distinct as the Four.
Another alteration would the first Spiderman movie with Tobey Maguire. We still get the origin of Parker getting bitten by a radioactive spider but the alteration would be the webs Spiderman now can create organically. Does this change the dynamic of the character? I don’t think so. Sure in The Amazing Spiderman we are treated to another origin story but this time Parker creates the web shooter ala the comic book origin storyline. Again, did this change Parker or make him more like the comic book series? The movie sucked but Parker was the same as this did not enhance the character. His ability to create webs either organically or artificially was not as important as his ability to use the webs and swing through the city. Now, if you look at the video below of a Japanese version of Spiderman, I would have gone apeshit if this were to happen here.
So, Hank Pym didn’t create Ultron in the MCU; I can live with this alteration. I’m more concern about Ant Man sucking like Thor 2.
According to Joss Whedon, “Of all the heat I’ve ever taken, not having Hank Pym [in the Avengers] was one of the bigger things.” However, Whedon contests that it didn’t make sense to bring in Ant-Man into Earth’s mightiest movie heroes.
In an long interview with Empire Magazine, Avengers: Age of Ultron director Joss Whedon explained why Marvel kept Scott Lang away from the rest of the Marvel gang, and why the comic creator of Ultron (Ant-Man) would no longer be the villain’s creator in the Marvel Cinematic Universe, but Tony Stark.