I don't think Jon and Liz are married. They're just dating.
One thing I have learned about newspaper comics in particular is that safety is key, especially in this fragile time for newspapers in general. While I seriously doubt there is ANYONE who buys the paper just for comics, readers may react negatively upon the removal of their favorite comics. A prime example would be Peanuts. It has been several years since Charles Schulz's passing but his comics are still being published in comic strips. Why not? Everyone loves Peanuts. It's the first comic many people gravitate to (including myself) when they pick up a newspaper. On the other hand, the newspaper is using precious space for this already established, beloved comic as opposed to letting a new comic artist start up their own strip. In this sense, it is almost impossible to become a syndicated comic artist. Statistically, you are more likely to become an A-list movie star than a syndicated comic artist.
This can be applied to Garfield as well. Many people agree that Garfield is past its prime, but it is safe. People know this comic strip and it is more likely to draw an audience than a new comic drawn by Joe Nobody. I for one hate to say it, but newspapers are a dying breed and newspaper comic strips are an example of this. Space alloted for comic strips has been getting smaller and smaller. In general, the paper itself has been getting smaller and smaller as well. I guess it's to save on paper. Which gets no opposition from me.
The good news is, there is still a future for comic strips on other media, such as the web. In fact, there are many possibilities for the future of comics.
Wow. I'm sorry. I went on a complete tangent.