What? The canonical book on this was written by Elizabeth Warren, it's not exactly a conservative idea.
The basic model as she describes it is that since spaces in 'good neighborhoods' and good school districts were fundamentally limited (by space and law), adding a second income to a family did little to increase their wealth - all of the extra earnings were devoted to bidding up a supply-limited resource. Middle class families roughly doubled their earnings but saw almost no benefit for it.
There's further evidence for this claim from the left, too. Piketty discusses overall inequality, but Rognlie persuasively argues that much or all of rising inequality in the US is attributable to skyrocketing land/housing costs. This isn't some trad-con claim that women working is a problem, it's a claim that what should have been a massively positive change for families in the middle class and below was consumed by a certain group of rentiers, resulting in more work without more wealth.
edit: I missed the word 'all' in the last line of the parent to your comment - I thought it simply said "not the fault of feminism". That... changes things quite a bit. This wasn't an inevitable consequence of women working, and the implication that the proper cure would be women not working is hideous. Apologies for the misunderstanding.