On the options desk that I was a quant on[1] the traders were extremely dismissive of Taleb's math chops since in his book "Taleb on Risk: Managing Vanilla and Exotic Options" he clearly doesn't understand delta hedging, which is a pretty fundamental concept, particularly if you're writing a book about managing options risk.
[1] Equity Exotics and Hybrids at Goldman in London circa 2005 or so.
Ok, the guy is not some Fields medalist, so it depends what you mean by math chops, but here are a few of his papers published in respectable journals that have non negligible math content:
He's also quite a bit less self-aggrandizing.
Otoh, they do seem to like reach other, which in my book does cast some doubt on taleb's ability to judge people...