Well, it takes two to tango. I'm reluctant to lay the blame on one or the other. But it is a pity to lose the facility to buy one ticket on two or more airlines in a single transaction and in a single currency.
It's too bad that IROPS payments are at the heart of this, as that is only part of the story. Surely they could have agreed to disagree on this aspect, but maintain the ticketing agreements.
(IIRC - IROPS is not part of the multilateral interline agreements)