Comic book authors
Creating a universe is a tricky thing. You have to name places, characters, concepts, and, in the Marvel Cinematic Universe, a lot of mission codenames. Thankfully, as the series is based on lots of comic books, a lot of the work is done for the new writers, but there are frequently new characters that need realistic-sounding names.
Marvel writers like to use these names to reference different things. Sometimes it’s obscure characters from the comic books, or sometimes comic book writers themselves. For example, President Ellis in Iron Man 3, is named after Warren Ellis, who was a writer on the Iron Man comics.