It's that it's a KEY MOMENT in source material.
I love it when directors create new stories based on my favorite characters, but I would appreciate they respect the source material at hand.
At first, I was, as I said, just very disappointed in Joss, I atill loved the Avengers, then when everyone who didn't kiss Joss's ass got called a bitchy fanboy, this was my reaction.
(I'm a brony, deal with it.)
Now, since you have called me that, I am not going to hold back.
First, while this isn't like Batman's parents being alive, it IS like someone other than Bane breaking the Bat. It's something you don't do because it would show that you have a lack of respect for source material, and in that lack of source material respect, you will lack respect for the characters that made the comics great.
Hank Pym creating Ultron is a DEFINING MOMENT FOR THE CHARACTER.
No matter how "bitchy" we are, or how "brilliant" Joss and Feige are, you can't change that it was one of Hank's defining moments.
Some users have argued that us comic book fans betray almost every director, and normally I'd agree, but it's actually the opposite this case.
We literally placed trust in Joss and Feige to bring the MARVEL universe to the big screen in a unique way that, while taking creative liberties, knew when to respect the source material.
So in the end, call me bitchy all you want to, because I will stand by my opinion until this movie comes out, and I will speak with my wallet AND my voice.