Re: Thor 2 Dark World news, speculation and pictures possible Spoilers - Part
Because Marvel is too afraid to dwell into what Thor is these days, because they fear protest. They don't even want to call him god of thunder anymore, its prince of thunder these days. In the comics Tony rationalize Thor's magic, by believing its highly advanced science that he can't comprehend....yet. But Thor is not an alien, he is god from a different realm. And yes they should all, Stark in particular, have reacted to both Loki and Thor. But seeing as his father dealt with cosmic cube(captain america movie), he probably already had some knowledge of other wordily beings.