Say your next product was in a domain that would solve a direct daily problem for the lead dev at this shop. By needlessly being judgemental (the people were "damaged"? Is that really how you go through life?) you've lost the opportunity to sell him your product. In other words, you've prevented yourself from furthering your long-term strategies / from implementing your overall vision for no reason.
More simply, there is no possible benefit in acting this way.
It may be gratifying, but you've constrained your future options without gaining anything decisive.
By not dominating the thoughts and feelings inhabiting your mind, you are being held hostage to primal instincts. Merely avoiding annoyance is not worth it when the cost is high.
> It may be gratifying, but you've constrained your future options without gaining anything decisive.
My point is that you don't know that. Different people have different goals and metrics for success. Avoiding dealing with annoying people may rate much higher for this person than for you.
Too little self discipline is a problem, where "too little" means not enough to allow you to do what you consider important. This doesn't mean that more is better. Discipline is a tool, not an end (unless that's your personal definition of success).
Ok, look at this: lead dev sees that your product solves their problem, but refuses to buy it, because you walked out of the interview.
And this somehow makes makes more sense than leaving interview at a company that you think is wrong fit for you?
More simply, there is no possible benefit in acting this way.