Why do people go out ony snake that they see?

I am totally agree with you, and I believe that we are teached to hate snakes, in our western culture, since people associate them with evil. People should value all the creatures in this planet, and consider all of them as equally valuable and beautiful, it requires of course, a lot of education. There are people low educated and cruel, who should learn to appreciate all living beings as important. I have seen people doing the same with stray dogs and cats, wich is of course, something cruel and inhumane.

There is a psychological reason for that. Let's see the chronological order below. We know, human is also categorized as an animal. As we know, animal has an instinct. Instinct will coordinate body in order to achieve its primary task; to survive. Not only is western culture, but also in eastern, snake is related to an dangerous animal which often to attack blindly. When we spot a snake in anywhere, our instinct as an animal works to protect and survive (while cops works to protect and serve). Note that human's instinct is different with any other animal. As a result from instinct response, we often found ourselves trying to eliminate the threat before we get threaten. In other words, sometimes we unconsciously kill that snake, without thinking twice. So, I suggest that when we encounter a threat, please don't be panic or we will be overwhelmed by our animal instinct. Make sure that we can relax so we can think clearly by common sense. Don't break the natural food chain. Don't kill snake as long as we can avoid from it. Old proverb: Do not destroy what you cannot create.

I agree with you that it is wrong on the part of people to kill snakes just out of fear or spite. Snakes are not only useful (this includes the poisonous ones) and an important component for any bio-system - they have as much right to this cosmos as we humans, or any other creatures do. Incidentally, even the rats have some utility and besides, they too have as much right to the space that we share as we do. If you look at it from natures point of view, humans are the most destructive elements in creation as per our current knowledge. Maybe, one day we may (I very much doubt it) some form of life that is more destructive and anti-nature creatures than we humans are.