Drive by trolling, nothing more nothing less
re: the killing of Coulson- I think knowing it was a Whedon movie, it was pretty likely *someone* would die, and tbh they obvs couldn't kill off Thor, Cap, Hulk or Iron Man, doubted it would be Black Widow, Hawkeye or Nick Fury, so it only really left Coulson or Maria Hill. And seen as we didn't know Hill before this one, it was the obvious choice I suppose