Part of it is just how Nazi recruiting and attempting to get a foothold works. They see a subculture with disaffected youth and societal outcasts (especially young men) and think of it as an opportunity. All subcultures have to remain vigilant because Nazis will do their best to subvert and appropriate anything and everything that they can to try to spread their socio-political disease.

Some more current examples are gaming, the chans, and fitness clubs/events (ex. Spartan Race). Not all of them are filled with Nazis but, they have been used as recruiting tools.