He was a Jerk. So was his wife.
That was what brought them together. For one, when he stopped arguing all day and night with her, Mrs. Robinson kicked him out of the house, only falling back in love with him when he attacked the Waterson's shed, and cut off Richard's tie.
Oh yeah. The Watersons. Their eccentric neighbors, a cat married to a rabbit, pff. And they treated a pet fish like a son!
But heck, they were a strange couple. Even Gumball, who idolized Mr Robinson, said "I don't know what he sees in that woman".
But, without each other's company, they would have no one to talk to all day, even if it meant arguing.