Linux survived because commercial vendors poured in over a billion dollars into making it a viable UNIX alternative. Microsoft's feeble attempts to sabotage it are pretty much irrelevant in that regard.
It's easy to call it "feeble" because it lost, but the worst-case outcome would have ruled the POSIX API was copyright SCO (funded by Microsoft), making it infringement to distribute Linux.
Linux could have survived in peaceful co-existence without the corporate billion. It would have been smaller and more hobbyist. It could not have survived if all the judgements had gone the wrong way.
