The conditions which prevail on Earth appear to be common throughout the Universe. Planets appear to form around many, if not most stars. Terrestrial -like planets and Jovian moons may both provide potential abodes for life. The fundamental chemistry of life is simple and naturally-occurring.
Evolution drives life toward increasingly varied and complex forms.
It is possible that exotic chemistry or other phenomena could yield forms of life that would be completely unfamiliar to us and which could survive in completely foreign environments. However, let's start by sticking to what we understand. Carbon appears to be the most versatile atom for chemistry and water is an ideal solvent.