Venus sounds lovely, but as for me, I prefer a Mars bar.

It isn't unrealistic at all if the odds of abiogenesis are prohibitively small. We can imagine all sorts of events with vanishingly small possibilities. We might not be able to wrap our human minds around the numbers involved, but that's kind of the problem: we look at the size of the known universe and say, well surely, x must have happened at least once. But without a sense of the probabilities involved, we simply do not have any reason to say whether x has happened or not.

There are plenty of conceivable events that happen precisely zero times (things that would violate the laws of physics), and we can imagine possible events that never happen at all -- simply because they are so unlikely that not even trillions of years of interactions between gazillions of particles will bring them about. We might posit that somewhere a teacup from the 1972 Sears-Roebuck catalog is orbiting a planet made of leather. This is certainly possible -- in the sense of not contradicting physical laws -- but it is so unlikely that, no matter how vast the universe is, we cannot be certain that such an item exists. Abiogenesis might simply be one of these mathematically highly unlikely events.

I'm actually not as skeptical about extraterrestrial life as I sound. I do think that, given the tendency that compounds have of quite naturally bunching together into slightly more complex compounds, it does seem reasonable to think that life is fairly abundantly distributed around the universe. But we simply don't know enough about life or about the universe yet. For aught we know, life could exist in the cores of neutron stars and on every god-forsaken rock in the universe -- or just here on this little blue rock for the past few billion years or so. Nobody knows.

Agreed. PBS SpaceTime posted a really excellent episode the other day outlining the challenges that silicon-based life would face in (most) natural environments. I, like OP, had long assumed that our preference for "life as we know it" was a bit of a blind spot -- I no longer think so. There are so many obstacles standing in the way of the organic evolution of silicon-based life that it wouldn't make sense (in most environments) for nature to favor silicon over carbon.

Given a) the goldilocks scenario that gave rise to life on Earth and b) the apparent dearth of life elsewhere, I think it is reasonable to suspect that it is very difficult for complex life to spring up just about anywhere. Silicon-based life would face an even steeper degree of difficulty. Environments without water (an ideal solvent for the mixture of molecules) might just render the appearance of complex life next to impossible. We can't know that for certain, of course, but I think it's completely reasonable to narrow our search (for the time being) to environments that seem conducive to life rather than expending energy and resources on locales where we have no reason to think that life is even possible.

Sounds like Titan needs some liberatin'.

A couple years ago, I used parallax to triangulate the absolute depths of my own fucking ignorance. I don't recommend it.

OP also appears to labor under the assumption that humanity is run by a tightly knit cabal of Very Rich People, Probably with a dimly lit boardroom where they kick back and sip Canada Dry and discuss which Projects to expend human capital upon. "SHALL WE END GLOBAL HUNGER?" "NAY, PISH-POSH, TOTAL ANNIHLATION VIA CHATBOT IT IS, HEAR HEAR!!!" ... and so on.