tomayto, tomahto. You won't get a strong defense of most of particular values for the drake equation from me. The question that remains is which of our guesses are wrong and why?
>Another perspective is that, as we've understood better how our EM radiation percolates for space, radioastronomy basically can't find anyone who isn't in our solar system (except maybe if they directly try to talk to us).
There are other aspects of the universe that don't agree with common assumptions about how it should appear if it were swarming with technological civilizations with a billion year head start on us. For instance we have yet to detect any stellar/galactic engineering. Then again I'm not particularly convinced by our assumptions about a billion year old technological civilizations.
Another perspective is that, as we've understood better how our EM radiation percolates for space, radioastronomy basically can't find anyone who isn't in our solar system (except maybe if they directly try to talk to us). That means that even our failure to find life via SETI isn't evidence of anything.