It is always a bit funny when you defenders of the bubble argue one minute that all the risks are tiny, default rates are still (now) minimal, etc., and that the CMHC is a well-funded cash cow.    No risk of any crash, ever.  Small losses, if any, etc.  IF that was all true, why have the banks spent the last decade insuring the vast majority of their new mortgage lending??  Why buy portfolio insurance in all the cases in which you don't have to??  Why have we heard of banks NOT wanting customers with bigger down payments??  Because they know perfectly well that their interests are better protected by taxpayers than by a slightly larger down payment...
All your arguments re the CMHC were made in 2006 about Fannie Mae and Freddie Mac in the US, and they went under pretty quick.