To be honest, most people watched Ant-Man because Paul Rudd was in it. They didn't know or care about the character, but they know who Paul Rudd is and generally the quality of his movies. They went in expecting a super hero comedy featuring Paul Rudd. They did not walk away disappointed.
Captain Marvel is going to be a much harder sell, but it will benefit from the fact that she will be in Infinity War first, so Disney/Marvel will be building anticipation for her stand alone film much like Captain America Civil War did for Black Panther.
I agree with the sentiment the real reason this movie is getting bashed right out of the gates is the insistence Marvel had on finding a *female* director rather than simply a great director.
I also agree there is no other hook for the movie right now either in lore or in the way of actor or director for the mass market to hang their hat on.
As others said, all the secondary characters had another draw. Rudd for Antman, Cumberbatch for Strange, large presence in Civil War for Black Panther. If Captain Marvel only has a little screen time in Infinity War - which is likely considering the sheer number of characters they're going to be dealing with - it had better be a massive role if they want it to boost the movie.
I think Ms./Captain Marvel is a fine character in general. Though she's no Captain Mar-Vell and never really had a presence in the decade I read comics.
And I think Wonder Woman will do fine. It may not beat 80 million domestic opening weekend but I don't think it has to. It has some serious star power behind it and I think people are ready for a different AAA DC hero on the screen other than Batman and Superman.
Also, no Zack Snyder which is a huge plus for me. I guess it will all depend on the Villain. Since so few regular people really know anything about Wonder Woman (even the Linda Carter TV show) they have a ton of great material to work with.