You need to understand that those symbols are not banned because of countries that used them and because of things that those countries did but becouse of ideology that is behind them. Nazism is about killing people, or even whole races. Communism is about equality (in its bases it's very positive and has nothing to do with totalitarianism, it was just directed the wrong way). And thats what makes symbols of those ideologies treated in different ways.
Disclaimer: Im not nazi, anti-nazi, communist or anti-communist.
See? What you are saying doesn't make sense, the national socialist idea was about national unity and as such it did promote the german race as the best one, just like fascism was about making Italy as great as it was at the time of Rome, I.E the best one, that's also what USA propaganda is doing nowdays.
Now, you are looking at nazism not at the ideology itself but at what the regime and hitler did when they were in charge (WW2,the holocaust, and various other massacres), If we were to apply the same way of thinking to communism, then the communist ideology is about shutting the free speech down,killing or deporting anyone that doesn't agree to the ideology, a total disregard for your own men's life which ends with a body count perhaps as high a 60million of people killed between gulags and in-action by suicide charges.
Why im writing all of this? Because the first thing one thinks when he sees the swastika is the holocaust, but that symbol is not what caused the holocaust, it's not the one that executed it either, it was the work of a madman with a twisted mind.
But yet, when one sees the communist symbol, all it comes to mind is the perfect happy place where the common folk could live happily as it was a paradise, and it was very very far from that.
It's a stereotype portrained mainly by games, it's like "oh no you can't have a swastika because it's the symbol of all evil incarned in the world!" which it really isn't, I mean hell, in the link I showed in my previous post it even explain that current neo nazi groups use the Imperial Germany symbol as their flag.
I want to add, that no, im not a nazi, im not a communist either, but I try and WANT to look at history in an objective way and my desire is for other people to able to do the same, and as I've pointed out before, this stereotype of the swastika needs to end once for all and guilt must be given to those that truly deserve so.