Shining is a well liked book. Clockwork Orange is, also. Bad examples. I am talking about a good version of something that has a bad foundation. Most Stephen King based films at least have a decent foundation, and Clockwork Orange did as well.
Avengers 2 is making changes, yes, but Marvel has been good about incorporating newer elements and such into their ideas while keeping the heart of what the title stands for. Their biggest change is the Mandarin, who I wouldn't call a BAD villain. He is a racial stereotype, yes, but he is still a decent comic book villain. Granted, Marvel changed him A LOT, and the end product was a solid movie IMO (though many argue that one in fandom). Pym's version of the origin will never be declared bad. Making Ultron a creation of Stark is for pure conveniance for the plot, and it sort of makes sense.
What they're doing to Doom is not element incorporation. What we're seeing is a direct adaptation of an inferior version. This is not like giving Stark a public identity like in the Ultimates, or having SHIELD help bring the Avengers together. The heart and soul of the 616 characters was maintained in those translations, and with Doom, we know he is part of the experiment, and he directly looks like his Ultimate counterpart. This is a strong indication he won't resemble Doom in the way MCU Cap, Stark, etc resemble their characters with updates. I mean, even in the ultimate universe, they retooled Doom's appearance to look more like 616 Doom because someone down the line realized he looked stupid in their attempt to salvage him (though it failed). This is a straight up, poor version of Doom we're seeing.
I was in the FF board when the Story films were coming out, and plenty of people knew it was going to be bad before they came out, and I tried maintaining optimism during it. But in the end, they were right. All our worries came to pass, and both films sucked. This has the same feeling for a reason. All signs point to this being crap.