I'm curious, why does it feel impure? And why do you think the answer is "happiness shouldn't be a terminal value" and not "happiness shouldn't feel impure"? As for it being mainstream, why does that matter at all? Believing a brick will fall if you drop it is mainstream too, but is that a reason to reject that belief?
I can't express meaningfully why it feels impure. Being mainstream matters, because, in this particular case, I enjoy not holding mainstream opinion for the sake of it.
I don't think that it "should" anything. I have nothing but intuitions regarding how happiness should feel.
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