One thing that caught my eye is the presentation of "Universe is not filled with technical civilizations..." as data against the hypothesis of modern civilizations being probable.

It occurs to me that this could mean any of three things, which only one of which indicates that modern civilizations are improbable.

1) Modern civilizations are in fact as rare as they appear to be because they are unlikely to emerge. This is the interpretation used by this article.

2) Modern civilizations collapse quickly back to a premodern state, either by fighting a very destructive war, by high-probability natural disasters, by running out of critical resources, or by a cataclysmic industrial accident such as major climate change or a Gray Goo event.

This would undermine an attempt to judge the odds of modern civilizations emerging based on a small sample size. If (2) is true, the fact that we haven't seen a modern civilization doesn't mean it doesn't exist; it's more likely to mean that it didn't last long enough to appear on our metaphorical radar. All we know with high confidence is that there haven't been any modern civilizations on Earth before us, which places an upper bound on the likely range of probabilities for it to happen; Earth may be a late bloomer, but it's unlikely to be such a late bloomer that three or four civilizations would have had time to emerge before we got here.

3) The apparent rarity of modern civilizations could just be a sign that we are bad at detecting them. We know that alien civilizations haven't visited us in the historic past, that they haven't colonized Earth before we got here, and that they haven't beamed detectable transmissions at us, but those quite plausibly be explained by other factors. Some hypotheses come to mind for me, but I removed them for the sake of brevity; they are available if anyone's interested.

Anyway, where I was going with all this: I can see a lot of alternate interpretations to explain the fact that we haven't detected evidence of modern civilizations in our galaxy, some of which would make it hard to infer anything about the likelihood of civilizations emerging from the history of our own planet. That doesn't mean I think that considering the problem isn't worthwhile, though.