edit:oops, title fuck up: Doesn't that violate the motivation principle?

So RPW opposes sex before commitment and it's pretty understandable as it takes away the incentive for the male to commit (why buy the cow). Despite this, they encourage doing housework for the man, even if they are not financially provided for by him yet. In some cases, the couple doesn't even live together, in which case the posts I've read talk about the woman going over and doing these tasks. The thing I don't understand is why is this encouraged at all, if it takes the incentive away from the man to provide. After all, at a point where the relationship is committed but finances are not yet joined, the man gets both the benefits of sex and housework, whereas the woman gains nothing. RPW: Wouldn't it be better to wait with housework until being provided for, just as it's better to withhold sex until a commitment is established?