Can't qualify for residency? Didn't make the immigration short list?  Don't want to disclose overseas income and assets? Don't want to pay tax on it? 

Still want to live in Canada? Buy a house, send your kids to school? Then the ten year visa is perfect for you. All you have to do is  exit and re-enter every six months.

And bonus, unlike immigration levels where the Feds might face flak over numbers, they can just issue millions of these visas every year.