I don't see the logic there, but in case it adds to the conversation, I will say that I think that it is fairly clear that extremism is not inherently a bad thing, unless it is defined as such (rather than literally) - in which case I think the word would lose most of its utility in conversations like this.
I find "extremism" to be used as a pejorative that is better interpreted as "non-mainstream" nowadays. Most people labeled as extremist are simply just that, not mainstream. Infact it is quite cynical of those within the mainstream to use this pejorative, since it by sleight of hand assosciates any ideas that the mainstream does not hold with what most others see as "violent extremists, wearing white robes and/or bombing subway stations".
