I don't know if all founders must be hackers, I've knew a few hackers with a lot of experience in programing but with no idea of web design.
I really think Usability and Design matters.
Also a startup needs to be changing fast in code and design, so maybe you need both of them.
I guess so, what I really want to say is that at least the founder in question should at least give some effort to try to understand what we the hackers know so that they can have some sort of common point to agree || disagree on. :-)