Until our species gets rather better at quantifying the effect of communication mediums' on cognition I take issue with Mr. Katz's assertion. The semantic meaning of Erlang and prolog code is such that ideas can be expressed rapidly, in my experience. Besides, taste in syntax is like taste in tea: you might prefer a light cup of Earl Grey, I might like mine over-brewed and bitter. Prolog's syntax--and by extension Erlang's--is an acquired taste, perhaps; I like them both.
You of course have a point in that "you can't argue with taste".
However programming languages live and die by the size of their community. Erlang has, by choice of an over-brewed and bitter syntax, drawn itself into a niche much smaller than it deserves. The only chance to escape would be to adapt a more popular taste.
Otherwise it will eventually be obsoleted by a language "as powerful as erlang, but minus the arcane syntax".
Tea time!