> Why is this a desirable goal?

It doesn't have to be a desirable goal to everyone.

> The only driver that I can really comprehend is the desire for freedom and autonomy in less populated spaces.

You got one of the big ones. But not the only one. Other is survival. Here on Earth we are all one bad infection outbreak away from ending human society as we know it. We have all of our eggs in one basket. Even if we would have a stable foothold on the moon and mars we would still be vulnerable to gamma-ray bursts and crazy despots with nuclear armed missiles.

> We'll recreate the same problems we have here everywhere we go.

We do. There are still benefits to the people who are "taming the frontier". And that is enough for it to happen. We also see that even though human condition follows us different places have a different feel to them. Some places we got some things better while others worse.

> Compared to anywhere else we know about, Earth is an extremely unique utopia.

To a certain extent. We can adapt the environments to us. And we can adapt ourselves to new environments.

When I move to the arctic I leave my parasol at home and buy a coat. When I move to a gas giant I need to rethink more of my biology. Imagine if some of us can become a buoyant sail with manipulating appendages who feels as much home in the red dot of jupiter as a homid feels home on a dewy meadow. If we could I would for sure give it a go for a few hundred years, then come back and write a book about how it was.

The fact that this is not easy is part of the lure of it.