Asking what the function of a pet is, is like asking what the function of a friend is. Neither really has to do anything particular to be worthwhile. Having some sort of utilitarian usefulness is not what pets (or children, or friends, or relationships, or...) is really supposed to be about.
I think we just disagree here, and that's okay. I see my children and friends as completely different than pets. You're right - children and friends don't require some kind of function to fit into my life - but to equate them to pets doesn't make sense to me. I can understand that some one might want to have a pet for companionship/friendship (read: function) - but I think it's different than human companionship and friendship. And for some it may be BETTER than human companionship (I have several friends who feel this way). I was merely sharing that it's something that doesn't fit into my brain. I probably sound like some kind of wacked out pet hater... I assure you I'm not.Asking what the function of a pet is, is like asking what the function of a friend is.
No, it's cool. I get it. I wasn't trying to equate the two, merely asserting that the reasons for having either are similar. It is certainly a different sort of companionship than what humans provide, but it is a form of companionship -- in my opinion, a simpler and usually far more honest one -- and those differences are, for pet people, part of the appeal.