Absurd? I'm definitely more confident that Fish/Zsh will stay free forever without changing their incentives, licensing and pricing than a YC-backed startup whose primary goal is to make money.

I generally try to avoid startups and either go for established companies (business offers are more likely to stay there and work as expected) or small bootstrapped business (cheap, more likely to stay true to their roots, do one thing well without breaking everything in the future).

Startups are good for free trials as they have VC money to spend or finished deals (purchase once, consume once, forget about them).