The Dink Network

Skull - I believe this comes from the fact that aside from Dink, none of the characters play a major role (aside, from, possibly, Milder). We know very little about them (and Dink's universe). Even King Daniel is little more than some random guy who gives you the last quest. You don't even learn about Seth and his attempt to Take Over The World until the very end of the game.

I believe Martridge is in quite a few D-Mods simply because of the fact that he's the only "true" wizard in the game (the Acid Rain guy looks like a farmer, and the secret wizard is a weirdo), and it's easy to make him a helpful (if somewhat incompetent) friendly wizard who will assist you and/or give Dink a quest.