I don't know if they've jumped the shark. The redemption issues started with the consolidation of airlines made worse by the current economy and cutting back of flights.

While never easy, I used to have a much easier time using my miles and now I'm finding I'm paying more and more with upgrades becoming increasingly scarce.

In the past, I would mostly pay for hotels and use carefully collected and hoarded miles for the air. I've begun to think about doing it the other way around, at least until availablity gets better.