By that same reasoning everyone should be doing their best to avoid runaway climate change, yet here we are. The tragedy of the commons is tragic.
Things are more civilized in space, maybe in part because of the relatively small number of big players. But at the same time there are tentative signs that we might be in the early stages of Kessler syndrome. It's hard to tell, and by the time we can tell with certainty it might be hard to still act in time
I think the difference is "perceived cost of the catastrophe". Many parties believe or choose to believe that all the damage done can be reversed, or it can't be that bad (which is very wrong, BTW) or, I'll die anyway, who cares.
For space, this perceived cost might be higher so, the limited number of parties might be more cautious.
Indeed I'm aware of The Tragedy of Commons, but from my view, space is a bit more nuanced.
Wish we were much more diligent about our planet though. We, humans, pillage it like all resources are infinite. Sad.