Nazifurs in 2017, a lot less actually white than nazifurs in 2007, still a lot less snazzy dressed than the nazis of 1937. A Trump tweet here would end with "Sad!"
How 'serious' they are kind of strikes me as a moot point unless one starts becoming a prominent politician or one buys a camp compound complete with crematorium. The danger of National Socialists doesn't come from their ideology, but their persuasiveness to the general public. In that sense, most people who generally reject the skinheads shouting will not give a shit if the speaker suddenly becomes a mediocre fursuiter.
What is specific to Nazifurs is edgelord attitudes, as such, I can see exactly why the RMFC put out such a statement. It's kind of irrelevant how nice of a Nazi this Foxler guy is or what his group has/hasn't done with roomblocks.
Moreso it's just important the con doesn't for good or ill become about them, their notoriety. People coming to the con should do so for the con not to see/punch/heil a nazifur. You could ban them, but that gives them a lot of license to stir trouble, and the nature of such a group is few can be pinned for doing actual bad stuff, so many friends and associates can still come in and cause headaches. Cons run on a thread as is, the staff really doesn't need PR issues or saboteurs in their ranks. I don't even think it's cowardly to downplay them, it could be both pragmatic and a step towards long term strategy.
Am I wrong? How would you show you wouldn't be divided? Should that random trashcan get lit on fire?