I don't think this is a swipe at Rich Hickey, unless it's considered a swipe to call someone out for repeatedly making misinformed statements about things they don't understand properly.. which is what Hickey does a lot in his talks, about Haskell's type system in particular.
The author says that Rich Hickey has built a speaking career on emotional appeals to the superiority of dynamic types.
I would prefer to say that Rich Hickey has built a dynamic programming language which includes a powerful typing system and that he's largely responsible for its design.
