Without any disrespect, this is why you (or 99% of people on the internet) aren't running a movie studio or directing blockbuster movies. *Nobody* thought the world even wanted, nevermind "needed" a "Guardians of the Galaxy" or "Ant-Man" movie until they saw it. It's like all the people who thought Bryan Cranston should be Lex Luthor just because they saw that he could be bald, or freaked out when the guy from "10 Things I Hate About You" was cast as the Joker...
It seems that anything could be a good movie or a bad movie .... just depending on the story and execution. And with HQ, it wouldn't surprise me if she has a supporting cast - she'll just be the headliner, the way Cap has been the last couple of movies... or not. Who knows?