Sure, some mathematics is outside the purview of programming. Certainly some programming activities are only loosely mathematical. But to say that the clerical part of programming is all that matters (and that's really what he says here) is totally ridiculous.
Agreed. It's true that math and programming intersect insofar as one is trying to prove the consistency of imperative commands (either by proving isomorphism with the lambda calculus or Hoare triples or something) but even writing something boring like WordPress invokes algorithmic thinking. You have thousands, possibly millions, of connections coming in a minute and don't want to thrash the database and want to ensure eventual response to all. Sounds like some pretty intense algorithmic thinking to me.
Sure, some mathematics is outside the purview of programming. Certainly some programming activities are only loosely mathematical. But to say that the clerical part of programming is all that matters (and that's really what he says here) is totally ridiculous.