Spaceman spiff
Noble
I agree - given what we now know about the universe, we should be expecting the fairly routine visitation of our planet by more advanced civilizations than our own. The ETH is only an "extraordinary" hypothesis if one has lived under a rock for the last half of a century.
I tried to explain this to Mick West a couple of times, but he prefers to pretend that scientific knowledge about the universe halted sometime in the last century...before we knew how common Earth-like worlds are in the universe, and how much older they are, on average, than our own planet (roughly 2-3 *billion* years older than the Earth).
It would be harder to explain why we weren't being visited by extraterrestrial intelligences, if there were no UFO reports at all. Which is why Enrico Fermi asked "where is everybody" back in 1950.
Yet we still have some people pushing the "rare earth" hypothesis. Like here again.
Does Intelligent Life Exist Anywhere Else? Here Are the Chances