I'm not sure that's "catching on". One would think that if they can't reliably offer a service, they shouldn't be offering it in the first place.
At what percentage 'failure' rate (that is can't be shipped in 2 days) should they cancel 2 day shipping?
You don't use Amazon, and that's ok, but it's usually very reliable. In my case, it wasn't even Amazon, it was UPS that caused the delay. The automated delay based refund trigger, that costs them losses in shipping, is at least evidence that they're aware people don't like delays.