The misanthropic principle, also known as the unthropic principle, is the philosophical argument that observations of the physical Universe must be, to some extent, incompatible with the conscious life that observes it. This is opposed to the anthropic principle.
It is self-evident that the vast, vast majority of the observable Universe is utterly hostile to the development of life in general and human beings in particular. Most of the Universe consists of empty space at about 2.7 kelvins (270 degrees Celsius below freezing), with nothing but an atom of hydrogen every few cubic metres and frequent bursts of hard cosmic radiation. Of what's left, the majority comprises balls of hydrogen so gigantic that they are spontaneously undergoing nuclear fusion, liberating enough energy to keep nearby space thousands of degrees too hot for complex organic molecules to form, if indeed there are any higher elements around at all. Discarding stars, most of what's left consists of cold balls of hydrogen orbiting those stars, and frozen rocks in deep space. Small, rocky planets with breathable atmospheres are extremely thin on the ground. Earth itself is the only serious candidate host for life, and even Earth has enormous problems with it: exposure to asteroid impacts, tectonic activity (volcanoes, earthquakes, tsunamis), hostile ice caps, hostile deserts, hostile weather (hurricanes, tornadoes, floods), a surface that's 70% uninhabitable due to being covered in water, large predators, stinging insects, debilitating diseases, and so on, and so on.
According to the strong misanthropic principle (c.f. strong anthropic principle), this is deliberate. The Universe was clearly built by a god or gods with the specific intention of studying the relatively straightforward behaviour emergent from what we call the Standard Model - stars, black holes, galaxies, superclusters, quasars, asteroids, and so on. Basically, balls of flaming gas with rocks going in circles. In order to prevent intelligent life from interfering with the otherwise more or less deterministic behaviour of the Universe, it was deliberately engineered to be as hostile to life as possible. This Grand Experiment has, of course, failed to accomplish this simple design goal. We are the icky mould growing between the gears of what was supposed to be a totally sterile piece of equipment. The Universe's creator or creators are fallible and we are their mistake. The whole thing is a write-off, and must be scrapped and done over.
This is clearly a powerful and instructive metaphor.
The weak misanthropic principle is, realistically, closer to the truth. This states, analogously with the weak anthropic principle, that although the universe isn't specifically designed to be hostile, all life must face some form of hostility. Equivalently, no lifeform is ever perfectly adapted to its environment. In fact, it would be highly suspicious if the natural world did work perfectly for any species or individual.
Whether the weak misanthropic principle is true - or conversely, whether a totally perfect organism can theoretically exist - is an interesting question. Still, once God wipes the cosmos clean like an Etch-a-Sketch the whole point will be moot, so I suggest forgetting the question and drinking beer in a boat. All life and all humans may face difficulties, but that doesn't mean contentedness is impossible.