S3, There are various possibilities why this is so:
1. Some earth-like planets are still evolving into higher forms of life. 2. Some have humanoids who are still developing a civilization that could transmit and receive radio waves. 3. Some have humanoids who have evolved quickly to unity consciousness and have attained god-like qualities, such as omniscience, flying through the air, and appearing/disappearing anywhere and anytime in the universe. 4. Some had humanoids who had died out as a species compared to the other forms of life in their planet. 5. Some have humanoids with advanced technological capabilities who are intent on conquering other worlds for power, money and gain. 6. Some have humanoids with advanced technological capabilities but are leaving Earth to develop on its own as part of its policy of non-inteference.
