Victor, when extremists of any kind are ignored they'll find a way to get talked about and to progress their agenda. If, as a society, we do not reject their behaviors, then public perception of these behaviors will slowly drift towards "acceptable". While 1940 germans had mostly no clue what was happening in concentration camps and were horrified at the discovery, they still decided to go along with all sorts of other anti-jew (and anti-polish and anti-not-germanic in general) behaviors because influent people told them those people were a problem for a solid decade and no on opposed those influencers in any meaningful way.
Opposing neo-nazis is not just about "educating the ignorant", it's about determining who we are as a people, as nations. The USA was founded by immigrants on values of openness (mostly for the sake of this argument we'll forget about the Indian wars and the slavery bit as one might argue those were standard for the era), you need to fight them because they are attacking the core values of your nation. They wanna be openly nazis? They can go do it in the Philippines, I hear they have a voice over there nowadays (provided you replace "jew" with "drug addict").