Putting it in a poorly-drawn web cartoon doesn't automatically make a trivial observation funny. Isn't this the topic of, like, 438973489 blog posts and essays?
http://garfieldminusgarfield.net/
http://marmadukeexplained.blogspot.com/
Great arguments for transformative fair use if you ever need them.
But Garfield wasn't terrible. Go back and read the first five or six years of Garfield; at the time, it was a breath of fresh air.
But no good things last forever.