The offset seats also look like they create extra gaps for kids to poke their hands through and annoy people in front. Or if you're really unlucky, someone's gross feet.
If your feet enter my space they become my property to do with as I please. In fact if anything enters my space unannounced I assume it's a gift from the flying gods and act appropriately. This includes people reclining their heads into my face. My heavily breathing onto your face while I stare at you sleeping because you jammed your seat into my knees is just rewards. It helps not being afraid of breaking social niceties in order to enforce them on others who can't be bothered to do them. In the same token poor new parents with screaming babies get my sympathy. It's hard enough trying to coo your child while feeling horrible about messing with everyone around because your family lives somewhere else. Adults and children old enough to know better... That's another story.