I got the impression from them that they wanted more than 40 hrs a week from me, almost to the point of wanting to own me. One of the managers had a problem with me continuing to support my own apps after accepting the job.
For me, that's a pretty steep job requirement. You'd have to really convince me that what you're doing matters and that lives are literally at stake if I don't come join your company. Otherwise you're just being selfish in my view.
I told them I can't accept the job unless they give me more details, and you're right, there's a good chance they will show me the door.
But then I'm pretty sure that's a business I wouldn't want to work for anyway.