Being recognized does not make something popular. Popularity has to do with something being well-liked, not just well known. Thor and Captain America are not popular characters. They are second tier characters in comparison to Batman, Superman, Spider-Man, and the Hulk. Why do you think they put Wolverine and Spider-Man in the Avengers comics?
Because Bendis was putting together his big anti-Bush manifesto in Civil War, and he considered Logan and Parker (and the rest of the New Avengers) to be the best representatives of blue-state America versus the red-staters in Stark's Mighty Avengers. It was purely a political move on Bendis and Millar's part.
Why do you think all of the characters I listed had major motion pictures made before Thor/Cap? The problem here is you are thinking like a comic geek and not like the general public.
Since you glossed over the part I wrote before, let me reiterate: so you're saying that Blade, Daredevil, Elektra, Ghost Rider, and The Punisher are all more popular characters than Captain America and Thor, both to comic book geeks *and* mainstream audiences? Because, you know, all of *them* got films well before Thor and Cap.
And I notice that your premise that Marvel Studios magnanimously "invented" Thor and Captain America for a blindly oblivious and gracious audience that had "never" heard of these characters before fails to even remotely take into consideration the abject failure of TIH back in '08. I suppose you're going to extend your fantasy even further and tell me that *Hulk* was unknown to the masses, too.....?
Viewers embraced the idea of Thor because of Iron Man 2 and the Avengers hype. Sure, the movie made more money because it was well reviewed but that has nothing to do with how difficult it was for Marvel to make this movie and sell it. That is my whole argument about how you aren't giving Feige and Marvel their props for making a quality Thor movie (with an unknown actor) that was a hit movie. Green Lantern didn't do well because the movie looked ridiculous and those impressions were confirmed once the critics savaged the film. A bit too harshly in my opinion.
Seriously? You *seriously* believe that the reason people went to see Thor or Cap was because of IM2 and the post-credit Avengers seeding...? The vast majority of audiences went to those movies to see those heroes stand on their own merits. Hell, Feige and Marvel made it a point again and again to emphasize that's *exactly* what they wanted viewers to take from those movies --- their solo efforts instead of thinking of these (and the IM movies and TIH) as Avengers prequels.
Look. I *want* Marvel Studios to succeed. I *want* them to have another blockbuster or three beyond the Iron Man movies. But the numbers don't lie --- Thor, Cap, and Hulk (in that order) fall wayyyy behind Iron Man in box office and merchandising and other residuals. Nobody, least of all Feige, wants RDJ to carry this studio on his shoulders all by his lonesome, but so far, that's *exactly* what's happening.