Form : Function : Existence?

I was thinking back to that design interview that I bombed out in.

At the time, I was showing the interviewer my albeit rushed portfolio, and was telling the interviewer about my smart phone app that I has designed for a project. I explained that a lot of research had gone into the topic before I decided upon it, and I explained its importance in providing a better alternative to the current for the target audience.

The interviewer asked me, "What was more important? That it looked good, that it existed, or that I worked?"

I explained that the visual form of the app was decided upon after the functions were determined, but it was not possible to separate the importance of the app to exist as well as to function, as these things were intertwined. His question did not make sense to me. There is no use in the app existing if it does not function as it should, and there is similarly no point in the app's ability to function and to improve daily life if it doesn't even exist.

I felt like I was being tricked into the age old form:function argument but this time with an entirely new element.

In any case I do not think he liked my answer, though he is notoriously hard to read.

What are your thoughts on this subject? What is more important to you, that it exists or that it worked? Or do you agree that they are inseparable elements?