Isn't life inherently bad?

You bring up some good points, which make life less pleasant. However, there are also many good feelings in life, which people enjoy. For most, these outweigh the negative sides. It can be difficult to argue "good" vs. "bad", but life is certainly popular: for us sapient beings, life is a choice. If we do not work to sustain ourselves, we die. If people disliked life all that much they'd end it. (and some do)