I think this is fine for excusing the social quirks of individual contributors. If you're talking co-founders, though, I'd consider this "caveat" a red flag. If a person can't bring himself to make a positive impression to other human beings because he's too enamored of the "idea and doesn't care for the looks," he probably doesn't have the requisite maturity to co-found a business that will employ people.

Of course, some people really are all talk and no action. But I suspect you're assuming too strong a correlation with social skills. The fact is that there are plenty of brilliantly social people who can and do execute, and plenty of smart introverts who can't. I'm not saying, "go into business with your friends!" I'm saying go into business with people you trust and respect.

The corollary is to become someone who is trusted and respected by people who don't share the same skills and biases you have. Good places to start: seriously consider whether "the looks" have merit, and practice carrying friendly conversations.