He's not alone in being a turd to someone because he fears victimization, more's the pity; most of the reason that Mike is a shit to Liz is because he thinks that he's being backed into a corner by someone who wants to use her cuteness to get him kicked out of his home and be laughed at and hated. Similarly, Liz presumed to hate Therese because she thought that the woman wanted her to die alone and be isolated from her friends and never, ever be approved of by the family that has no time for her.
Why all this condemnation of the inoffensive because of the misapprehension that they seek a Patterson's utter destruction when all they want is to be left in piece? Simple; the Patterson thinking along these lines lusts for the power to dominate others but doesn't want to admit it. This requires that the viciousness in his or her own darkened heart be projected onto others.