Listen, I'm having a full on nerdrage meltdown on Twitter over this and apparently so are alot of other people. Case in point:
Marvel's even had to cop a plea cause apparently the writer's been getting death threats. lol.
Anyways, symbols fictional or not are important. Captain America has long been a symbol to people. He was created in the 40's to fight Nazi's. Not become one.
His entire character "works". The displaced 1940's boy scout do-gooder who actually believes in mom, Jesus and apple pie...works.
He was bullied and became something bigger and stronger and fights against injustice. Works.
He puts his sense of justice...of right vs. wrong above all else, even allegiance to whatever government happens to be in power and has walked away from being Captain America & fought other hero's for it. It works.
HE LIFTED MJOLNIR! HE NEVER COULD HAVE BEEN A "SECRET" NAZI AND DID THAT.
CAP AS A NAZI DOESN'T WORK.