I used to think a lot about this (and like this) after hearing Ildjarn and reading about him. It always amazed me how a seemingly simple and obscure individual can create such music of revelation and mistery.
But really, I don't believe in honesty, at least not as applied to artists, or creators. They are, above all, beings that give shape to the confusing realm of reality, and they do it first of all through the strength of their spirit, a sublime affirmation of their own existence. Furthermore, I do not know how much they actually understand about the True meaning of their works. I think that conceptualization is better left for critics, and contemplative natures in general, rather then active, creative natures. Their works of art often have a life of their own, beyond what could be expected, or implied.
Of course, for Burzum and Ildjarn for example, they were fully aware of the atrocity or the moods they wanted to convey, but just because it is not conceptualized, and is seemingly simple, it does not mean it holds no philosophical merit (and philosophical would go better replaced with meta-physical). I guess when they talk about being your True Self, it is akin more to something like bringing forth my own vision without hesitation or compromise. Now of course, in the case of talented and exceptional individuals like these BM musicians, the expressions of their visions and feelings about the world are worth a check, and the ones from the Moat guy are worth shit. That's why any loser may consider himself true, and that's why even if I try to mimic the simple songs of Ildjarn, and may succed at it, it wouldn't be of the same value, since both approaches would be fake: we do not share the same spirit and we have none if we are stuck trying to mimic others.
That's why not any "unfiltered expression of your true Self" has worth for every dude out there. We are not equals, and brilliant, creative individuals are a rare breed. Music that is fake means just that the creators are shit / not interesting / boring / imitators / expressing human weakness in both form and content / unable to transcend their own knowledge for expressing something both new and eternal / not worthwhile.