Some day this world will be barren and lifeless and totally uninhabitable. I’m not defending Space X, but sooner or later we’ll need to leave. I wouldn’t be quite that dismissive of the need to get out there, but that’s not as urgent as the environment.
That’s a best case scenario. A gamma ray burst could hit the planet tomorrow and we’re all gone. A madman with a bunch of nukes could trigger a nuclear winter. A massive volcano could darken the skies for years - wouldn’t be the first time. I’d like to see some progress just in case.