Agreed. The brothers each (separately, and not to each other) go out of their way to stress that they do still love their brother, but that they're just rubbing each other up the wrong way all the time. Chet speculates it's because they are together ALL THE TIME; they're at school together, at home together, solving cases together (I think they don't share a bedroom at home any more, but wouldn't swear to it) that would be enough to drive anyone nuts eventually.

Even their father has admitted (to Mrs Hardy) that he, along with everyone else, tends to think of them as "The Hardy Boys" rather than as two individual sons with their own opinions and approaches to life.