"That's Great!" you might say. "Now everyone will make more careful decisions."
Except what will actually happen is people will stop forming companies, since they will be completely liable for things outside their control, like the bad decisions of others or stock market crashes or the weather.
The US corporation system is by no means perfect, but the protection it allows people who are actually trying to create things (read: not patent trolls) really does foster innovation a lot of the time.