I posted a quote about the long term not being a good guide to current behaviour.
We get an astoundingly high return on the space race.
There is not one part of our technology that has not benefited from it.
We have better metals for our knives and other trinkets, and we bounce signals off satellites to call for help when we get lost.

I don't think we will ever discover signs of ET, and even if we did it would take so long for the signals to get here from there that they would already be extinct, or we would if it was going the other way.
But still the return in technologies is so high that we should continue trying to get off the planet.
"Mars today, Tomorrow THE UNIVERSE!!!"

Besides, if the universe really is undeveloped we might be the first to be able to capitalize on it...