I don't get it.

This t-shirt seems to be causing a controversy:

"It's all relative in West Virginia." From the AP story:

[West Virginia Governor Bob] Wise said the T-shirt depicts "an unfounded, negative stereotype of West Virginia." "I write to you today to demand that you immediately remove this item from your stores and your print and online catalogues," Wise wrote. "In addition, these shirts must be destroyed at once to avoid any possibility of resale and proof be given thereof."

I don't get it. Is the joke that the state's name merely relativizes it to another state, thereby undermining its integrity or completeness? That's a stereotype? (And if it is, it's surely a founded one.) I feel like I must be missing something.