Since the very beginning of Heavy Metal, bands and musicians have sought to differentiate themselves from one another. With a slight change of style, a different riff, different clothes, or a few different influences, suddenly you have a new sub-genre. While this concept can, in fact, help to categorize metal or music in general, it really doesn’t seem to me to add anything to the culture of metal.
I find the descent of metal into sub-sub-sub genres annoying. We all have bands we like and bands we don't like. I don't think you should disqualify any bands based solely on sub-genre, no more than you should validate them for the same reason. If you like the band, support them. If you don't, well, good on ya. Me, I like metal. More than that, I like music. Metal will always be my first and greatest love, but I like electronic music, I like pop music, I like experimental music and jazz music and blues and on and on. If someone can skillfully take elements from different places and make something interesting out of it, that's awesome. Doing so shouldn't be a way to further isolate people.
What the fuck is “Post Metal”? Is that like metal music that comes after metal? What does “Crust” or “Sludge” as terms add to the music? Do we need to have something called DSBM or Djent or Mathcore?
How does this labeling do anything but confuse and isolate? Do we need to classify our music the same way we classify insects? Maybe I'm rambling and maybe I have the wrong perspective, but I feel like Fear Factory and The Scorpions and king diamond and cannibal corpse all come from the same source. Yes, they are all very different, but the concept is just the same. If you ask me, I'm just a metal head. If you like metal, I respect that. If you like metal I don't like, I respect that too.
Individuality has always been the core of my personality, and no one should be shamed for striving towards that. That said, digging deeper into obscurity is not required to set yourself apart from others. What you do should differentiate you, not what you call what you do. To some degree, this type of sub-classification is impossible to escape, I have just always found it annoying and alienating. Long hair, short hair, leather or denim - we're all metal heads. Let's just be happy with that.