Mark, I would be truly very surprised if they stopped making ink until nearly the last of their printers using these inks bites the dust. Firstly, ink is probably the only thing they make money from in this market niche (OK, perhaps paper too) and secondly, it would be a PR debacle if they left a large number of owners suddenly high and dry. That is most unlikely to happen. And as you say, they could perhaps sell their patents to third parties.
As for corporate bean counters - I think we both know that these companies are in business to make profit and keep their shareholders loyal and happy and their managements handsomely paid. That is the "name of the game". You wouldn't want to be running HP at this juncture of its corporate survival. It may be one of the world's largest technology companies, but it is facing massive fundamental challenges. It is purported to be the biggest PC maker in the world, but where is the PC market going? It is purported to be the biggest printer manufacturer in the world (all types, not the ones LULA folks use for fine art printing), but where is the printer market going? These are life-threatening issues - it is well beyond bean-counting, and if you were trying to manage a behemoth like this you would be poking into every nook and cranny of the enterprise and the external environment it faces to see what's holding its own and what isn't, where economies can be made, and what the strategic direction of the company needs to be if it is survive into the next decade.
All that said - you're right - it won't be the first time nor the last that good technology gets sacrificed to economic realities and financial interests - and people who don't control these decisions lament them.