User blog comment:YoungOtakuNerd/A Bit of a Strange Realization.../@comment-1431602-20130622053349/@comment-4797970-20130622215014

Basically, I'm saying that Porky can't truly be percieved as evil. He was misunderstood, and Giygas sought some opportunity to corrupt him. That corruption stuck with him for a while.

Also, fun fact (warning, potential spoilers): in Mother 3, Porky has some memorabilia of Ness and Co., such as the Friend's Yoyo and a movie of them that plays at a theater in New Pork City. I see this as a possibility that Porky actually appreciated them. (spoilers are over.)