I bear no negative reactions towards those who used to predict what life
would be like in the distant future year of 2000 A.D. They gave it their
best shot. They also tended to be on the optimistic side (quite refreshing
from today's general attitude of doom and gloom). Had certain people,
groups, corporations, and governments been a bit more thoughtful and
interested in their children, we might have had a lot of the better things
they envisioned by now. So I neither blame nor ridicule those past
prognosticators for our present lack of what they predicted.

Though a bit often too sarcastic and pessimistic for my tastes, this site
offers some samples of what our recent ancestors thought things might
be like by now:

http://www.davidszondy.com/future/futurepast.htm

As for SETI (to explain again), the whole point of the paper was to open
up ideas for the field beyond radio and even optical. And yes, there was
justified wondering and lamenting at how Mainstream SETI, which one
would think is a cutting-edge science, is still mainly relying on ideas and
principles going back over 50 years. Searching in a few new realms - is
that going to hurt anyone? Taxpayers can't complain any more.

And yeah, it would be nice to have more data on certain subjects, but
then if we did I guess we'd already know if and where at least some ETI
existed, thus solving one problem. And I am still waiting for more than
eyewitness accounts before I start buying into ETI actually visiting
Earth in person, or at least via their machines (or course advanced
ETI might also BE their machines. See, it is tough to get past these
old paradigms, but I keep trying).

Going back to the predictors of humanity's future, they had only one
species and one world to get their ideas right on. So of course they
were more than likely to miss the targets (but as I also said, a lot of
that came from people not following through on some of their ideas,
such as space colonies).

But we've got over 70 septillion star systems in the known Universe
(and probably a lot more than that), so that's 70 septillion chances for
at least a few ETI to develop along the predicted lines. I know certain
people here don't seem to like or care about such amazing numbers and
odds, but that doesn't make it any less a plus for the possibilities.

Add in the fact that if you are an advanced technological ETI with a
growing population and extensive knowledge base, you are not going
to survive very long by remaining on one planet with finite resources -
especially not when you can utilize both an entire system of worlds
and there's a giant nuclear fusion reactor that works for billions of
years at its center. Unless you are a suicidal species, you aren't
going to just sit there and let all that bounty go.

Maybe it's all wrong. Maybe advanced ETI will tap into the vacuum
energy of the Cosmos or absorb energy from an alternate universe
without permission, so they won't need to build Dyson Shells or
Ringworlds.

Or maybe they'll prefer to spend their lives in a virtual reality existence
and ignore the rest of the Universe. Or maybe they'll all regress back to
their equivalent of jellyfish. They'll probably be a lot happier at that level,
at least until they get eaten by predators on a regular basis.

But just note that the presented ideas are based on logical extrapolations
of known physics and not completely wild and unsupported claims. You
have to start somewhere, especially when we're just a bunch of smart
primates who have only begun to figure out some things about existence.