If I had to pick a sticking point for WW, it would be the belief in the Greek gods in the modern age. While those gods are the source of her power, most writers of her books like to hit you over the head with them time and again. She becomes the poster child for ancient Greek religion, and becomes one note.
My impression is that the DC Universe, like the Marvel Universe, has interpreted the gods of classic mythology as some kind of higher being that isn't literally divine but some type of sci-fi surrogate. I think DC's Greek pantheon is treated as the same class of being as Jack Kirby's New Gods (Darkseid and the like).
And stories about ancient gods existing in the modern age aren't unprecedented. There are the
Percy Jackson books and film, for example. Or "Who Mourns for Adonais" on
Star Trek, though that went the "they were really aliens" route. Heck,
Hercules: The Legendary Journeys did episodes claiming that at least one or two of the Greek gods survived to the present day. And it's worth noting that in the 1970s, Filmation's
Shazam!, about a present-day superhero with the powers of multiple mythological figures, was one of the biggest hits on Saturday morning television (although the entities that gave him his powers were portrayed in only a very limited way in the show).
As for the
Thor movie making the Asgardians aliens, I think that's just because they're putting the film explicitly in the same continuity as
Iron Man, The Incredible Hulk, Captain America, etc. Audiences have no problem with fantasy films set in the modern world -- look at
Harry Potter. But the general, non-comics audience would probably be confused by the kind of indiscriminate blending of fantasy and SF tropes that's commonplace in comic books.
Or it could be about marketing, the same reason they're putting HYDRA logos in place of swastikas in
Captain America. I notice that the current
Avengers cartoon identifies Thor and his people as "Asgardians" and avoids referring to them as gods. The toy companies might be uncomfortable with the possible reaction from the Bible Belt if they try selling figures of "pagan gods" to children.
Of course, there's no reason an adaptation of Wonder Woman would have to focus as heavily on the mythological aspects as the comics do. I don't remember the gods ever showing up in the Lynda Carter series.
See, saying "Wonder Woman wouldn't work because of this one specific thing" is misunderstanding something about the character. The main reason Wonder Woman has had problems with her popularity is that she's so
many different things. There are so many different facets to her character and her mythos, so many different angles and interpretations. It's been hard to pin down a definitive take on who and what she is. Yes, she can be a mythological champion, and that's been played up in the comics and animated adaptations of recent decades. But she can also be a patriotic American symbol, a champion of gender equality, a heavy hitter in the Justice League, the core figure in a "stranger in a strange land" narrative, an embodiment of a romantic ideal, an object of fetishism, an earth mother, an Emma Peel-style secret agent, you name it.
I once read an essay that made an interesting point. There are lots of different male superheroes that can share the load of embodying aspects of manhood and male identity. But Wonder Woman is called upon to be the singular superheroic standard-bearer for all things feminine, and that makes her too complicated to pin down as having a single defining identity.