The cap on the survivor benefit means that CPP is not a pension plan, but instead is a state sponsored social program masquerading under a false label in service of a political interest.  

There are low cost areas of the country where that cap is not seen as a huge detriment, because the capped CPP + OAS + GIS provides sufficient resources to eke out a reasonable way of life.  Those areas routinely vote for politicians with a capital "L", and are thankful for all the extra little bones that are tossed their way from Ottawa.

The ROC pays for this, and this situation persists as long as enough clueless urbanites can live off their incomes, pensions and home secured lines of credit until they lose a spouse, when a good chunk of their retirement income disappears, and they find themselves in a considerable financial pickle.