Because nothing good can remain untarnished and self-contained:

Variety reported Tuesday a small movie company that doesn’t own It’s a Wonderful Life is planning an official sequel — somehow, for some reason, possibly because greed minus self-awareness. Tentatively titled It’s a Wonderful Life: The Rest of the Story, the superfluous production will show George’s grandson being taught a lesson by his aunt Zuzu, now transformed into an angel. The company is hoping for a holiday 2015 release so it can compete against Star Wars Episode VII and look that much more foolish.

So what else could they possibly do?