Whats the role of non-working spouse?

My wife hasnt worked full time on over a year. She didnt work at all for 6 months and the other six months she was part time. I work from 6:30 to 7 at night. Many times I would come home and she would be on the computer doing odd stuff. She wasnt actively looking for a job. Most times I could tell that she had been sleeping during the day. Or I would come home and still have to pay all the bills, balance the checkbook, file the bills, mow the grass, clean up after the dog she begged me for,etc.. Is it wrong of me to expect my wife to be working or doing something productive during the day while im out working 12 hours a day. We have a 11 yr old son whos at school most of the day so she had plenty of time to herself. If I questioned her day or what she had done she would be get pissed... What???