Thor is a lynchpin of the Marvel Universe. He's one of the "Big Three" of the superhero team of the MU, the Avengers. He's got a long and storied history as both a team player and a solo hero.
Storm has taken really big hits character-wise in the last few years, and marrying Hudlin's Black Panther replacement isn't helping her stature any. She's been removed from the team that defines her and has become a supporting character for Reginald Hudlin.
Think about that. We're pitting one of the most legendary heroes of the Marvel Universe against someone who is reduced to a supporting character in a poorly-written book.
Now granted, Storm is recognizable to more people outside of Marvel fandom, but Thor is one of the top dogs in the Marvel Universe, arguably in all of comics.