There are no business constraints. None. That expression is an illusion, a way peopel have of rationalizing their inability to make change.
There are no business constraints forcing peopel to make poor decisions. There are just people making poor decisions. In a big company making a collectively poor decision you have a larger aggregate of people making poor decisions. But they are still people making poor decisions, and there are no inviolable constraints, no laws of physics that prevent the company from making good decisions in aggregate.
The UX designer says wait 12-18 months for a redesign. Why didn't they redesign the site 12 months ago so we could see it today? One or more poor decisions twelve months ago, that's why.
Other companies like ING and Apple get it, which tells me that There are no constraints, no laws, just people who zigged when they should have zagged.
If Dustin wants to shout that the emperor has no clothes, I'm happy with your ad hominem suggestion that he's a six-year old boy. Maybe that's what companies like AA need, a little boy to say "You could have everything, happy customers, an understandable web site, AND 3,459,798,345 in profits instead of losses."