It is not so much about house duties being horrible, humans can endure harsh conditions with the right mindset. And that is exactly the point here: the mind set connected to the work. House work is fine and all, but if only one partner is doing it and the other one doesn`t appreciate that, it can get on your nerves, especially over a long time. Think about it: Your whole life after marriage was raising the family and doing housework and then that isnt appreciated by your partner. That is not a nice feeling.