They refuse to create more use case because they don't actually have plan to make their project became more bigger. Provably those CEO's you work for is only for sales and target only to gather more money out of their ideas that's why they didn't listen on suggestions given. This action they made is actually a big red flag since as you said they didn't listen for anything and most provably they aim to scam people.
Do you really believe that I would work for scam projects or are you just in need of an extra post for your signature campaign? I would say the former.
No, I thoroughly research the projects that I work for and I never work with a scam project that has nothing to show but an idea. I work with real people, real teams and projects that have already created something with hard work. Most of the time this means an MVP (Minimal Viable Product). If they cannot show me that they have put in a lot of time, money and hard work then I am obviously not interested in working for them.
The problem of them not listening is mainly the fact that they have gone too far to back out of the project. That is what I mean by ego.