But what is and isn't "half-baked prototype"? People/users/media/investors confuse GUI with functionality with "addresses actual use case(s) for users who might pay/subscribe".

I'd rather have something with a brutal/nonexistent GUI but provides useful functionality and gives me a warm fuzzy that the developers have some use cases in mind, or a suggested workflow.

Yes there is a first-mover advantage to getting into a domain early.