I'm not sure I buy the "coalescing multiple things into one makes things simpler" argument - the simplicity comes at the expense of expressiveness, flexibility and optionality. A large, highly-opinionated monolith, right the way across the stack, is bound to have made some design trade-offs and decisions that are either plain wrong (we all make mistakes) or don't fit with however I want to actually use it.
To do this at the AST graph/language level strikes me as both genius and absurd - not only is language design very hard, but you clearly have a massive uphill struggle to provide sufficient library and framework-level code on top of that to be able to start to compete with more mature options. Not to mention things like code review tooling (it's neither text-based, nor even in any form of conventional revision control system, so likely start from scratch). Security controls, auditability, vulnerability management for any library ecosystem that springs up around this, etc. etc.
By rejecting text you are having to reinvent and support a compiler, an IDE, github/gitlab (or equivalent, with their massive functionality set including protected branches and security controls and the like), package management maybe, debugger tooling (on the web), release/rollback systems/UIs, perhaps even monitoring and alerting (because you're promising the users they don't need to run infrastructure/services like Prometheus and the like and your "roll out" process looks so different).
Does Dark really have sufficient expertise around all of that to want to make this stuff totally monolithic? Is it even possible for a startup company to really compete in that sort of global (massively open source) scene?
Convincing people to bet their company on your company, both as an ongoing enterprise and as a place that can get all the inherent trade-offs here well-matched to their individual use-cases is going to be an almost impossible sell. Regardless of how much you assert that you believe in your mission and don't want to ever pivot. You can't blame people for being sceptical, especially when the opening paragraphs essentially say "this is a silver bullet".
I wish you luck.