I don't think open sourcing is going to fix their adoption issue. Like the other comments mention, you need to be worth the time investment to gain traction. If Dark was truly as revolutionary as it was marketed as, it wouldn't have had problems staying source available, IMO. Folks will pay or put up with whatever it takes to be in the ecosystem (such as CUDA).
I agree it won't fit it, but IMO it will remove one of the barriers to adoption. The problem with doing something revolutionary, is that it's only going to be revolutionary in some ways, and it has to compete with things that are mature in ways you are not. And the original version (now called Darklang-Classic) was quite immature in an awful lot of ways that made it difficult to build on.
That's being addressed with the new version of course!