His bathroom doesn't have a basin so he goes to the loo and washes his hands in the kitchen sink over his dishes... that's disgusting.
Dunno the history (gives a bit more flexibility: a showerer doesn't constrain the toilet), but could also be an aversion to not clean yourself in the same place you poop.
Urbanites became absolute cry babies, bring them to the farm for an hour and they would starve themselves after they learn animals shit and veggies grow in compost.
Life is disgusting, get over it