the damndest things can be Turing-complete

Yep. Which is why letting a domain-specific language reach Turing-completeness is a danger, because when you can do something you will soon have to do it. I've ranted on this before.

Idle speculation: I wonder if this is analogous to the intelligence increase from chimps to humans. Not Turing-completeness precisely, but some similar opening into a new world of possibility, an open door to a previously unreachable area of conceptspace.