[eyelidlessness]

FWIW, the className prop is a React thing not a JSX thing. Other libraries which use JSX will happily accept a plain class prop. The React limitation is abstraction leakage: props are not attributes, they map to DOM properties.

But to the point that JSX is a DSL, that limitation is specifically because React itself is very tightly coupled to DOM semantics… but JSX explicitly has no built in semantics[1].

1: First sentence of https://facebook.github.io/jsx/ - “JSX is an XML-like syntax extension to ECMAScript without any defined semantics.”