Seriously, though.
Jon Arbuckle is a CARTOONIST. Not all people are good at cartooning, y'know. It takes a certain skill and talent to be a cartoonist. And yet some think he's a loser.
Also, he's a great cook, and he has the power to put up with a troublesome cat and a dumb dog. Yeah, Garfield isn't the nicest pet in the world, and he sure gives Jon a lot of trouble.
Now, sure, he can be immature and a (manchild) at times, he can come off as awkward sometimes, not to mention he's usually a casanova wannabe, but Jon is not an average person. He takes care of his pets pretty well, he can cook, he's a good cartoonist.
Fortunately, Liz finally became his girlfriend in 2006. Although Jon is still considered quirky.