I don't see it so much as gender roles, as how the US workplace has changed and what it takes to raise a family these days.

Most two adult families seem to want or need 60 to 80 hrs per week of paid labor to support their families.  A family can still achieve work-life balance in this range, but when as go over 80 total hours per week family life gets tight.  It would be great if two adults could split their total work hours however they like, but we often can't.  

First, at higher income levels a 40 hr job actually expects more like 50-60 hrs committment.  More if you want to make the big bucks.  It's rare that you can cut that in half (for half the pay) and keep the job.

Meanwhile a 20 hr a week job hardly pays anything.  With child care and the tax bracket of a higher paid spouse it's often not worth it.  So even if dad wants more time with the kids and mom wants to get out of the house, financially the best solution is often for dad (usually dad) to work the long hours to bringing the extra $$ and mom to stay home.

So the only way to achieve work-life balance for many families is for one parent to take 'work' and the other to take 'life'.  Which sucks for both.  But yes, if dad is working 60+ hrs I think it is fair for mom to be responsible for the housework.  Even though that's the suckier end of the deal.