> if people could spend part of the energy they give to TypeScript to also promote PureScript

Not quite. Promoting TypeScript is essentially promoting people to document their JavaScript. That is exactly why its so successful.

Promoting PureScript is promoting developers to use another language (and there are hundreds of those … many of which are better designed than JavaScript as they do not need to deal with a long legacy tail). If you want the JavaScript ecosystem, TypeScript is the best way to enter it safely 🌹.