It's not that Mark is wrong. He doesn't try to answer THE question, because there is no right or wrong answer. It's not so black and white, yes you should do it or no you should not. What he did was giving great advice that should seriously be considered, but the choice is up to you.

Read his advice, he tells it like it is. If you choose to do it, then you have answered the question for yourself. If Mark advises against it and you think he's right, indeed you're not an entrepreneur. If you do it anyway, simply prove that it's the right answer.