Nazi and German are not the same thing, and the difference should not be taken lightly.
Both SS and NKVD committed some of the worst crimes against humanity and have lost family members to both. With that said, I do not think that it should be glamoured or valued over it's face value. It's important to remember the history - but for me the line between historical piece and "yall, I got me a jew-killer" is just too fine. To collect something you have to have some kind of connection or admiration about the subject - and Nazis deserve neither.
Despite all the Stalin's atrocities - Mosin Nagant represents to me a common man fighting for his country against foreign aggressor, and even more so with Finn examples.
So, why would YOU want to own an SS weapon.
http://www.collectorsweekly.com/articles/why-would-anyone-collect-nazi/
Why would I??? Because of the history is why. WWII is a subject i am interested in. I'm not trying to bash on you because of your personal decision not to own a nazi rifle. I've just only heard it once before on another forum. To each their own. I have however owned yugo SKS's and mausers with "kill marks" in the stock and crosses carved into them. I've also had type 99 arisakas and everything inbetween.