Not sure if that's fair to Weird Al. The people he parodies wouldn't really agree either [1]. It's not like he's doing the cheap morning show tactic of swapping clean words for dirty words or bad puns but leaving the rest of the song intact. They maintain a consistent theme which is really tough.
Yeah, perhaps I was a little harsh. Don't get me wrong, I like Weird Al. I probably could have phrased my comment a little better. I should have said something along the lines of, "In my experience listening to Weird Al, it doesn't feel like he explores a lot of the English language."
[1] http://www.weirdalforum.com/viewtopic.php?t=5673