It's awesome. It's desirable for the same reason fast cars, fun computer games, giant pyramids, and sex is.

In sci-fi maybe. I doubt people actually living in space (or on un-Earth-like planets) would concur, without some very extensive technological change.

It's possible different subsets of humanity can never happily coexist, in which case having arbitrarily large amounts of space to live in ensures more peace and stability.

New incompatible sub-subsets will just keep arising in new colonies - as has happened historically.