Re: The other point of view
No down vote - fair answer.
But you elected to pay.
At issue, imho, are the people who choose a HP printer over a different brand because of the "free ink for life (of the printer)" plan. Marketing is about capturing people's attention and influencing their decisions. So every printer sold because of this plan was successful marketing. Since you make an economical point: that is something HP should have considered before launching this plan. They could have, and should have, imho, only stopped new subscriptions. Those that have it - should be able to keep it. As you say - it does not cost that much. Further, only more food to the fire about how HP treats it's customers. I had nearly forgotten.
Probably, there is some "fine print" saying they can change the conditions at any time - but morally, they are wrong. And, if you have been on the plan 5 years - how could this be a "introductory" plan started two years ago. I read this (between the lines) - they were not getting enough subscriptions - so a manager put his bonus on the line to get more subscriptions (not more money). Goal achieved - let's now milk the subscribers - because we can!