A few thoughts on the evolution of metal.

It is a form of folk metal that is made when Scandinavian folk melodies/rhythms/whathave you are infused into the riff work instead of simply the tacking on of folk instruments.

Sounds like you pulled that out of your ass. There's no reason to call what you described anything other than Scandinavian folk metal. 'Viking metal' (insofar as the term is useful at all) refers to lyrical content, but viking metal is not a genre.
 
Seriously... math metal is not a genre. I will listen to arguments for viking metal,even though I don't buy them, but math metal always can be reduced to technical _____ metal. There's no case where it can't be placed in another genre.

Now, I do not understand "technical X metal" being a genre. DOesn't that just mean it is X genre, but hard to play? In which case, it would belong in X genre. I think math metal is a more legitimate genre then any technical genres.

Think, what genre is meshuggah in? Not death metal, not black metal, not grindcore, doom metal, or whatever. What about dillinger escape plan? Not in any conventional genres either (maybe hardcore at a stretch). Fredrick thorenedals special defects? We could just classify them all as avant garde, I guess.
 
^ I agree to the extent that i dont care much for what has passed for folk metal so far. But i think that 95% of what passes as folk influenced metal today is anything but that. I havent yet heard a folk band to fully incorporate the folk music with metal,what i´ve yet heard is only some kind of pseudo-"put a flute here and a jews harp there" folk,putting one or two riffs that sound "folky" in the song and call it folk metal. I think that´s a genre which has a great potential if someone truly talented should take it on.
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