> why don't conservative men fall over themselves to fill that role?

Because it doesn't work. Women prefer uncaring[1], unpredictable[2] guys over dutiful housemates[3][4].

[1] https://www.ncbi.nlm.nih.gov/pubmed/22517110

[2] http://www.nytimes.com/2012/11/04/opinion/sunday/i-heart-unp...

[3] http://www.eurekalert.org/pub_releases/2013-01/asa-shw012413...

[4] http://www.telegraph.co.uk/news/worldnews/europe/9572187/Cou...