Imagine all of potential human knowledge is an island. It has fertile plains, mountains, lakes, and so on. Each of these areas symbolizes a different realm of human knowledge. People start out in a rich plain, where food is plentiful and life is easy. This would be the "Things you notice by looking around" area of knowledge, with information like "fire hot", and "food tasty". But humans like to expand, and so many leave the comfort of this easy terrain, and enter the nearby foothills of science, and even go into the mountains of mathematics and physics. They learn how to fish and swim and dive into biology.
On this island is a swamp. Early exploration of the swamp made it clear: the swamp isn't very useful, and most people have taken the position that there's no value to entering the swamp. Since the beginning, people have solemnly entered the swamp, and proclaimed themselves wise, and important, and every other virtue you'd care to name. They enter wearing white robes, and end up covered in filth before the first day is through. Not once has anyone brought anything of value from the swamp. In fact, the only activity that seems to happen in the swamp is flinging mud at other inhabitants of the swamp, and arguing over the precise etiquette of flinging mud at their opponents. If a onlooker comes too close, he may fall under the sway of these mud men, but most of the world is safe.
This swamp is Philosophy. Philosophy produces nothing except arguments. I had stuff about how the higher up the mountain of math you go, the more "pure" the math is, and how that becomes less useful, like how mountain climbers aren't exactly contributing to society, but that's not really relevant to insulting Philosophy, which is my thesis, I guess.