The biggest criticism I've heard is "I don't want my config language to be Turing-complete." I agree; nobody does. But two of the three config languages I used

The biggest criticism I've heard is "I don't want my config language to be Turing-complete." I agree; nobody does. But two of the three config languages I used started out as static no-frills languages and eventually became Turing-complete by accretion of need to support more and more complicated configurations, and given that they were headed there eventually, I wish they'd been Lua instead of a Turing-complete bespoke language with its own parser, its own (bad) error messages, little thought paid to debugging ("hey, it was never supposed to be complicated enough to need debugging!"), and no tooling.