We can assess probabilities, it is not hard to look at history and see where we have been. There are ruins around the world testifying that people do not always find the solution to problems in time. If people want to eat, drink and be merry because an asteroid might strike, it is up to them, but that kind of behavior can lead to death by much more common factors. I am glad you bring up the argument, John, so that we can look at it clearly. People need to be clear about what they are putting faith in, and what the history is.
Technology has a significant history of stopgap solutions, with dramatic failures.
There have been successes, too, as I wrote in an earlier post, we live by technology, a flint knife is technology. But we need to judge technology with clear eyes. To have built a population of 6 billion on mined resources was not looking very clearly at all, and to argue that it can be kept up indefinitely is not what I bet my life and the life of children on, history is not in favor of such a bet. If I have a way of life that looks sustainable for millions of years, I don't change it until you show me something that really offers an improvement. For example, I am not sorry to have a technology that might detect and deflect an asteroid.