First off, he shares Phil's love of playing head games with his love interests owing to a rather appalling need to make sure that the girl doesn't get any weird and crazy ideas about being an equal partner in things. Since both of them were brought up to believe that a girl is a silly, hormonal child who needs a man to guide her, this makes the two of them think that they're great guys living right.
Next, we have to contend with their shared belief that having to do things for others is a horrible and selfish imposition. I was as inclined to want to backhand John when he gasped in horror because his trains were threatened as I was Phil when he squealed about his housemates tossing hot dogs that sat in the fridge till they got covered in blue mold.
Next, we have to deal with their essential lack of a sense of humor. While ever ready to knock people down a peg to remind them that they don't rate, neither John nor Phil have anything like a sense of how absurd their own behaviour is. This is part of a general hypocrisy that allows them to not notice that they're doing the same damned things that they look down on other people for.
At least Phil was lazy enough to manage to avoid becoming a father. Five bucks says that if he did end up having kids, the son would be as big a jackass as the third man whose married status makes no sense at all: Michael.