Personally I think the pessimistic estimates are too optimistic. I doubt for instance abiogenesis has a 0.1% chance of occuring. Even the simplest self replicating system is staggeringly complex and still hasn't been reproduced in a lab. It happened relatively early in earth's history because it had to to allow time for it to evolve into consciousness, and maybe the conditions were more favourable.<br>Also I think that the rare earth hypothesis would put the probability at far lower than 0.01% for a habitable planet. There's like dozens of factors some of which seem to be truly rare such as a large moon.