I think since Benson appeared to be so deprived of affection throughout his life, the only way he would know how to show it is through violence.
Regardless of how deeply he felt for Randy, he could only express it by being aggressive.
Like if he got upset that Randy didn’t eat his food because he cared about his wellbeing and wanted to make sure he stayed healthy, he would express that by shoving Randy around and demanding he finish the meal.
Or if he wanted Randy to be more comfortable in social situations, he’d force Randy into interacting by threatening and insulting him.
Obviously it’s justified if it’s in Randy’s best interest.

















