It doesn't sit right with me either, though I think the protection for women had been eroded already (but now has much more clearly been removed)
I think it is a crappy policy. I will lose it which on an individual level is fine for me, but its not like someone who needs it is going to get my £20 a week added on to theirs (which would be great) and in fact it looks to me that people who are on lower incomes are getting royslly screwed.
Plus the looking at one income thing is just crazy, and it will probably cost more to administer and means test than it will save