If I dressed up as Darth Vader, it doesn’t mean I’m hell bent on galactic destruction. It means I’m in fancy dress.
You do seem to be missing the point. Darth Vadar is a fictional character, the Nazis where real – I know they both had films made about them, but there is a big difference.
Secondly, no one genuinely advocates obliterating Alderaan, whereas plenty of people do believe in Nazism and given half the chance would carry out atrocities in it’s name.
Choosing to associate yourself with the latter is pretty daft in my opinion, even if you think you’re being ironic.
But hey, if you really want to, be my guest, just don’t complain if not everyone thinks you’re being hilarious…