I happen to know when exactly this project was launched. And it was quite surprising to hear about it again, since it fell completely off the radar. Darklang came about the time when the backend was being seen as the bottleneck. The writing endpoints, server administration, deployments—"too many things to do commit simple operations on a database." Many products were launched to solve the issue, like Graph.cool (backends using GraphQL). Few other startups were about creating backends using drag-and-drop components (don't recall the names).

Things have changed now. People have started realizing the problems with such approaches. As soon as you grow beyond the experimental stage, you start running into more issues than what these solutions claim to solve. It's cool to create a simple backend without writing code/less-code, but what if you want to incorporate an integration? caching? mail-server? background jobs?

I am old enough to remember Meteor.js, too. A JS framework that raises millions and it was about writing real-time applications with a single codebase. It met the same fate. Felt into oblivion in a few years after the initial hype.

Pardon my pessimistic take, but I see no future for a different language taking off, no matter how high-level primitives it offers. The network effects are too hard to overcome. And honestly, a language, even if mediocre, can implement the same thing via libraries.