These days, I would rather hang out with my 3 year old son than do anything else, but there was a period where I was home for about a month and a half straight, and I'm just not cut out for parenting 24/7 (or ever, some might argue). I almost couldn't wait to go back to work because I knew it made me a better parent and less inclined to take my time with him for granted. Sad, but like somebody else said in this thread, maybe it's just a character flaw of mine. Then again, my wife is a teacher turned stay at home mom, and she loves it overall, but there are days when it even gets to her.
Come to think of it, there isn't anyone in the world--including a best friend, my wife or any girl I ever dated before her--who I could tolerate being around every minute of every day. And there is no job or recreational activity that I would want to do for every waking minute either. I know people who disagree, and work 19 hours a day and seem relatively happy, in spite of the fact that their hobbies and home lives have to be nonexistent.
I think most people need some balance in their lives. You get that when you work 8 hours and then come home to something else. You don't necessarily when you are a stay at home parent. I don't think there's much point in arguing about something inane like "how much work" various jobs entail.
I will admit that I'll occasionally crack a joke implying that my wife fabricates a lot of these "things" she says she's having to do during the day that keep her so constantly busy, and she doesn't think it's very funny.
-J