What if the copyright holder dies young?

Suppose you're a software freelancer, you're 35, you have two young kids, you've spent the last 15 years working very hard writing software, and you're able to support yourself with annual license fees from some businesses.

If you decide to just watch TV for the rest of your life, your hard work will continue to pay off, and your kids will be provided for. But if you get hit by a bus one day and killed, your one valuable asset instantly becomes worthless, and your kids aren't provided for.