Earth is indeed an interesting planet with great diversity, especially in terms of flora, fauna and cultures. This makes earth a very adventurous and exciting planet but also a separation-friendly one. In contrast to that, many other inhabited planets in the Universe are much more representing a specific core theme (e.g. technology) on which everything is built upon. In this case there might be less diversity on a global scale but on the other hand more development and enhancements in the specific core theme.