Our western civilization lacks an effective long-term (order of 50 years plus) self-preservation system. Hence we should reasonably expect to either build one, or get wiped out.

This is a huge claim. You're claiming first of all that the odds of succumbing to a truly existential event are higher than not. You don't (IMO) provide evidence to support this - you provide some evidence that we may have had really catastrophic events in the past, but, again, only 100% is existential, and you do not finish off your examples - "Hitler could have won" and "Hitler could have won and created a repressive regime that lasted for the remainder of human history" are two very different claims, and the former is not existential. Second, you claim that if we take some steps, we can expect such events not to happen - it is because we lack an "effective long-term preservation system" that we can expect to be destroyed completely.

Thus, you have, to my understanding, made two claims: one about the likelihood of existential events, and one about the likelihood of us being able to mitigate them. Again, to my evaluation, you have provided compelling evidence for neither of these conclusions; indeed you've provided virtually no evidence for either of these conclusion (probability, not possibility). That is the root of my criticism of not providing solutions: you claim solutions are possible, desirable, and effective, and you do not provide any evidence to support this claim.

Thus, my criticism of your tone as "righteous" is because you seem to be making a strong, "deep" claim without providing adequate supporting evidence or argument. It is not a criticism of your word choice. I have absolutely no problem with people posting about problems that occur to them that they don't know how to solve. I do have a problem with people making strong claims with a definitive tone without providing adequate supporting evidence.

I admit this may all hinge on a disagreement in definition over "existential." I take existential to require true obliteration. Gray goo would reach this, as would the-simulation-loses-power or every-atom-splits or humanity-is-enslaved-by-something-forever. "Nuclear holocaust kills billions and it takes ten thousand years to recover" does not count in my mind, as it is not terminal. Similarly, "Hitler reigns for ten thousand years" is also non-existential (at least for humanity as a whole); If recovery occurs, even after a fairly large gap, it does not seem to count as existential. This view is consistent with Bostrom's definition in the linked paper. With a weaker definition of existential, it is quite possible that there is no disagreement here, in which I have the (smaller) criticism that you should have clarified this at the beginning.