1. IAG (hopefully) isn't stupid enough to have done something that will warrant actual legal consequences, especially at the level for which the Adios devaluation decision was made.

2. They think customers will forget about it. And/or they've received a report from someone calculating that the loss of goodwill and willingness to post miles to the BA frequent flyer program is less than the costs that the program was incurring, particularly given that BA had already received payment for the points it sold to Chase and others.

In essence, what they pulled off was offering a land rover, accepting payment for a land rover(from a middleman at a bulk discounted rate), pocketing the difference and delivering a Kia instead.

The devaluation, the refusal to honor their contractual obligations(for India tickets resulting in mass litigation), and being the fee-happy industry exception to tag on charges and surcharges for otherwise routine line item expenses have convinced me never to post miles to BA. I still fly BA because they have a better hard J product than AA, but will choose the OW alternative(AA, CX) wherever possible.