Tort law is going to catch up to software soon enough and people will be held accountable for negligently creating or deploying software that they should have known would cause harm.

The fact that someone else down the chain should have known better is not a perfect defense. If that misuse was foreseeable and you didn’t do enough to prevent or discourage it, then you can still be held liable.

If startups prioritize their growth over the good of society, isn't the logical conclusion that startups are a threat to society?

They're not a startup.