Some German pilots were ardent Nazis, some weren't.
Some Soviet pilots were ardent Stalinists, some weren't.
Some Japanese pilots were ardent Imperialists, some weren't.
Some American pilots were ardent New Dealers, some weren't.
I personally think all of the above regimes, for that matter all "regimes" ever, were/are varying degrees of evil, yet I would still fight for my nation to the best of my ability against outsiders, and I believe any man worth his salt would do likewise.
The truth is, a combat pilot's core personality and ethos is more profession-defined than politically defined. Bud Anderson and Erich Hartmann would likely have more common ground and more to talk about over beer than Bud Anderson and Joe Pencil-Pusher. They were similiar kinds of men, they both had a genius for shooting down enemy airplanes, so of course they both hold similar fascination for fans of WWII aviation.