About extremophiles
The argument concerning life developing in very harsh environments because we see life here on Earth is dependent on one question. In what direction did life evolve? Did life evolve in those harsh conditions, OR did life evolve in more friendly environments and then slowly migrate into the harsh areas. Evolving slowly over time to adapt to those conditions.
An example are the worms, shrimp and crabs we see in footage of hot smokers on the ocean floor. We know that they didn't arise in that environment, but adapted over time to be able to live closer and closer to those vents.