The problem lies in the Income Tax Act, which says that you cannot have a pension plan unless there is an employment relationship, meaning T4 income. If you have someone working in the home, someone who is not remunerated, that person is shut out from the whole registered pension plan world. One quick fix is to scrap this antiquated rule and simply allow women who work in the home to participate in a pension plan.
The question is, where are they going to find the money to put into the pension plan? That is a broader problem, but at least if they have access to the plan, they can save for their retirement. Right now they're completely shut out; they have to rely on their spouse's pension, if he or she has one, and survivor benefits.
The supplemental CPP is not a silver bullet; it's just one way of tackling the problem. However, under that scheme, deemed earnings could be used, or there could be a lump sum amount, similar to what you have for tax-free savings accounts right now, with a maximum for each year that is indexed to inflation. They could say that you could save up to, let's say, $5,000 in the supplemental CPP, and that builds up every year. You could at least create a pension stream for yourself.