I agree that leaving money in RRIF can be problematic from the standpoint that the final pot is taxed at potentially max marginal tax rate on death of second spouse.

This issue can be even a bigger problem if one spouse dies relatively early.  Their RRIF is rolled into the second spouses and than the amount required to be withdrawn is now taken by one spouse and taxed at a higher marginal tax rate.

I am not a huge fan of RRSP/RRIF for this reason.  I think people need to consider the tax deduction vs taxes paid.  They work best for one spouse who has very high income and other spouse does not work so future withdrawals will be done at lower marginal tax rate.  

TFSA in my opinion should be preferred method of retirement savings for most middle income earners.  However don't spend it for a kitchen upgrade.  If you can save more than TFSA allows, some amount in RRSP should not be a problem.

Most do not think about withdrawal strategy.  They are lured by that shiny tax deduction.