It's actually even worse than that--they were originally writing a story that really was a sequel to Cap 2, and would have had resolution for the S/B story, and there was a whole other plot with Zemo than what they used--but when they found out about Batman vs. Superman, Feige wanted a big superheroes punching each other story to go up against them and force their hand. Then Downey basically demanded they turn it into a Tony focus if he was going to be in it, and that's how we ended up with fucking Iron Man 4 and Steve/Bucky pushed into the no-homo zone.