Aeroplan tried a similar move years ago and reversed course due to the backlash. Their compromise was that you don't lose your Aeroplan points if you keep your account active - either collect or redeem every year.

It surprised me that AIRMILES thought they try the same thing. Let's remember that all the miles were bought and paid for by the food/beverage retailers, or banks/card issuers.  A reserve is created so that when the consumer cashes in, the flight or other stuff can be paid for.  The fact that they have to reverse $200 million of income is their problem. I can't see how they felt the money was theirs in the first place.  They are the custodian of the money until the consumer decides how to spend the money.

I expect to see consumers flock to other rewards cards in large numbers.  I will continue to use my blue AIRMILES card, where you get something for nothing. But I will never again use my AIRMILES Amex. Better to accumulate a reward that will be there when I want it.