I think you're constructing a straw man argument to avoid talking about the central issue of shared housework, larry. Whether it's a job or not has nothing to do with whether both parties should pull their own weight at home and avoid treating home like a hotel and the SAHP like a domestic servant.
If we take an averagely demanding WOHP job, they are out of the house for, say, 12 hours. They sleep for 8. This leaves 4 full hours plus the weekend for doing household tasks. Standards can therefore be jointly maintained because both are contributing.
As an aside, if SAHP were a job, the clue is in the name - it's Stay At Home Parent, not Stay At Home Skivvy. So for the 12 hours they are parenting, not vacuuming.
As a further aside, I think it's very sad that the construct that you turn to in order to give wifework more social cachet is "working for the man". I know, let's give wifework the same titles as traditionally male roles, ie let's call it a "job" conveniently overlooking that SAHP is work that is very far from having all of the protections that brings, like a salary and employment law and a pension and so on.