The OP discribes what is one of the more crucial skills needed in critical sicumstances: take yourself out of the quotation, take a step back and decide after having seen the whole picture and not just a smal aspect of it that fits your personal preferences best. And then doing it, especially if it's just one big shlep.

What is actually the most dangerous thing to happen, simply because it's so convenient, is that by doing what you can do best all the time keeps you busy, in your eyes and the eyes of others. So when you fail, it was not because you didn't do anything. You're creating your own bubble.

That's why it's better to have a co-founder who is not a carboncopy of yourself and to have a not-awfully-bad board, because both can help to pop that bubble before it is too late.

Very sound advice, and not only for start-ups / founders but for everybody who has a certain responsibility.