I like Lillynix's view in theory but think it would not work in many circumstances. It sounds like her partner doesn't work excessive hours - is this the case?
I think it's unfair to expect anyone to work 12 hours at an office or wherever and then come home and do a couple more hours domestic work. Unless of course the other parent is doing that much work too, which could happen if you had a lot of kids or did some unpaid/volunteer work or something. But I'm sure we will all agree that at least some part of a SAHM's day involves coffee with friends, sometimes TV while baby naps, surfing the net. And that's awesome!
Getting a break at work from the kids and getting to go to the toilet and eat in peace doesn't make going to work easier. Whenever that is mentioned I think well what about the stresses of that persons job?! I know mine has its own and some would have way more. It's draining and exhausting. If I had to come home from a draining day and someone handed me a toilet brush I would be pretty annoyed. Especially if they could have done that task themselves at some point in the day without a problem. It's the idea of "saving" work for the other person that doesn't sit right with me.
I'm only talking about domestic chores here. Childcare is another issue but again that's not 50/50 in our house because of the hours he works. It doesn't mean that he doesn't deserve any time to himself at the weekend and if he occasionally wants to go out then I have no issue with that. He rarely does though as he wants to spend time with DS.