The Swastika symbol has also come to have its own more generic meaning too. as being a symbol representing intolerance and hate.   So one might spray paint it anywhere one thought that hatred and intolerance existed.   Many on the left have used it in protests against Donald Trump, as well as many other conservatives, for example.

So you are right that it is not necessarily a Nazi.   The Nazi movement is all but dead in our country.   The handful that still pursue it are generally imbeciles:  people with an extremely low IQ.   Many are drug addicts too.

Do you not remember that Nazi couple that had all of their children taken away from them by the state of New York 4 years ago?   The state proved that they were morons, and unfit parents who beat their children.   These are the kinds of stupid idiots that follow the Nazi ideology today.   Take a look:

https://thenypost.files.wordpress.com/2013/08/04-3n007-nazi_-c-525x6151.jpg