Is it okay to clarify to a PhD interviewer about a question that I was hesitant to answer then, but am not now? Today, I had a PhD interview and the interviewing professor asked me about my plans after completion of PhD. I clearly stated that I wanted to fund my own startup and setup my own venture, to which he cross-questioned that why do I need a PhD for founding a company. Even though, I tried to to clarify that my venture would be based more on the research that I'm going to do, he seemed a bit unsatisfied with the answer.

Finally, he told me that if I had any queries or had to say anything, then I'm free to mail him regarding this.

My real answer to his question "why do I need a PhD for founding a company" was that "I didn't want my years worth of research work to end up in some corner of an archiving website, where no one is going to take a second glance later. So, I wanted my research to bloom into a company for the public benefit."

But I was extremely hesitant to give this answer to him back then since it could have implied that his work is also in "some corner of an archiving website, where no one is going to take a second glance later" which would be extremely demeaning.

But, now that I think about it, I feel that I should clarify this stating this proper reason in an email which I gave above. 

Would it be a wise idea to do this? And if it isn't, is there any other way of putting it to express my idea to him?

All inputs are appreciated.
He is asking you why you need a PhD, he is not asking you why you want to sell your research. So, I think the focus of your response is misplaced; why does it have to be presented in a way that if you're not a CEO + PhD then you're a loser who will spend the life publishing shelf fillers?

Instead of comparing to (you + PhD + company) versus (other + PhD + no company), think (you + No PhD + company) versus (you + PhD + company.) 

There are dozens of way you can cast this decision positively without dissing the interviewers: 


The vigorous training in scientific thinking will enhance my credentials as a CEO.
I would love to work more closely with the R&amp;D so that I can better tailor my company's strategy.
I love to challenge myself, PhD is a great milestone, a trial for me to hone my grit.
I would love to see my research idea turned into a product that people would love, it's always been my dream.
There is a lack of research perspective in the current industry, I wish to change that.


Generally, try to project the difference between the normal you and a better you, not a better you and the inferior you. Some of the negative comments, as you said, may be hurtful even it's not targeted at anyone but yourself.