I recently flew to HAV on KLM and was confused when trip read ineligible mileage on my Skymiles account. This is absolutely ridiculous. I booked the flight without even thinking twice about not partner mile ineligibility. Delta flies to Cuba. Delta flights to Cuba earn Skymiles. Why wouldn't partners earn skymiles? After three attempts on twitter and a complaint filed online, I received a response explaining they couldn't give me a reason why this is the policy.

Where is there rational reasoning behind this policy?