One more point I would like to make about symbolism. It's great to have a symbol that means something. If your aligned with a party that has a swastika that's perfect for conveying the message that your ideals align with the ideals of the Third Reich. In that sense, it's a wonderful symbol for communicating your ideals. If your ideals don't align with that of the Third Reich, then using a swastika is probably a bad idea because everyone is going to think that you condone everything that symbol means.
However, these concepts apply to all symbols. Southerners in the United States in the mid to late 1800's cultivated a very specific meaning for the flag that became the symbol of their movement; namely, pro slavery. So, if you have ideals that don't match with this symbol, then using it will be a very poor way to communicate your stance on issues. It would be like someone opening up a charity with a swastika symbol. They can talk all they want about heritage, history, or how they have different ideals, but people are going to see that symbol and think one thing.
So, when a State has a symbol on its symbol -- a flag on a flag in this case -- they are saying that their ideals align with the ideals of that symbol. They can talk all they want about heritage, history, or how they have different ideals, but people are going to see that symbol and think one thing.
I'm not saying they should ban the symbol, we can all agree that would not be effective. I'm saying that a state shouldn't be using a symbol that means slavery, oppression, hate, inequality, and bigotry even if it also means history.