The video isn't nearly as raunchy as my title might have you believe, but it can be even more disturbing. I'll be honest, this video gives me chills every time I watch it. Even so, it's fascinating to watch the surinam toad give birth, being as how the male embeds the eggs on the female's back.
Okay, I can see that being another source of digust. I wouldn't have found that avenue myself. The things you mention do not disgust me, save if I imagine them happening to me.
According to some researches reason did not 'evolve' to provide us with truth or better understandings, but evolved to compete with each other for sexual favors.
People Argue Just to Win - Scholars Assert
According to an ancient mystic paradigm; reason is a divine property of the universe which is reflected in the mind of men; called the Logos and the personal Logos. Reason always aims toward truth but is stifled and misdirected by the corruption of the heart. Reason is then employed to justify and serve the heart, if the heart desires fame then reason will be employed in the acquisition of fame. Never-the-less reason for the sake of reason or truth alone, is destined to reveal secret truth.
You have completely misunderstood where this particular disgust comes from. I am not reacting to to imagined toads coming out of MY back at all. I believe this particular brand of disgust comes from how closely this resembles rotted flesh, images of parasites, worm-eaten wood, insect infestations and hive imagery, all of which have a visceral effect.
There is something to be said for disgust of this type, as it might keep someone away from similar things in real life, and thus prevent the spread of infection and disease. That being said, you're right about disgust (or any strong emotion) keeping one from making good (by which I'm guessing you mean rational) judgments and decisions. Sometimes your autonomous nervous system is specifically designed to override your rational mind, and that's not always a bad thing.
Disgust like this always bothers me, because it has a kindof blinding effect that leads people to react to the feeling of disgust instead of making good judgments.