I don't agree I am. On the contrary, there is a lot of philosophical debate on the relationship between pragmatism and truth – https://plato.stanford.edu/entries/truth-pragmatic/ – and I think what I'm saying makes sense if you assume a certain position in that debate (albeit one which I'd expect Benatar would reject)
Obviously, in the short-run, the popularity of a belief tells us nothing about its truth. But what about the popularity of a belief in the very long-run, in the limit of future time? If we somehow knew that, as t approaches infinity (or the future extinction of humanity), believers in a proposition will inevitably outnumber its disbelievers, would that in itself be evidence that the proposition is true? Personally, I say yes. I don't know if Benatar has written anything on this topic, but I assume he'd have to say no, since yes implies the falsehood of his published work.
> He is carefully building an argument that if we consider an axiomatisation of ethics where causing pain is bad and getting pleasure is positive, it can be argued that life is actually a poor deal
I think it is interesting, but for the opposite reason he thinks – if consequentialism/utilitarianism (or at least some versions thereof) produces that conclusion, to me that's another nail in the coffin of consequentialism/utilitarianism (or at least those versions of it).
> Parfit himself spent a significant part of his career unsuccessfully looking for an axiomatisation of population ethics
I've read Reasons and Persons. I think his discussions of the theory of personal identity are very informative, even though I don't agree with his materialist/physicalist premises. His contributions to ethics fascinate me less, because I don't believe in consequentialism, and I doubt ethics is axiomatisable
