From my reading of the blogpost, I don't see any reason to infer that he "didn't like demonstrating coding in interviews", per se.

He did suggest that some of the problems one gets asked to solve are gratuitously hard, which correlates with my own experience. He also fairly acknowledged that he was getting a lot of rejection for other, e.g. cultural reasons.

So it would seem that it's getting rejected, not "demonstrating coding in interviews" that he doesn't like.