Bear with me on this: What if we can't find aliens because they are religious?

[Pope George Ringo II]

12. Frequency is the question, admittedly.

But my understanding is that the end of the second generation (or so) is when stars actually start to produce interesting elements from a biological and technological perspective, so it's likely everybody circles one third-generation star or another, especially if we limit it to technologically advanced societies. Our own window is quite brief, and we're getting better at finding data in the background, but we've really got just the tiniest glimpse at the bigger universe. Okay, maybe we see nearly everything in our little corner, but only as it was for just a brief and variable moment. Heck, we've only been doing serious telescopes for a few centuries, and we're not even two centuries into serious radio reception.