Let's not take my comments out of context, OK? This is what I said...
An airline has no legal obligation to make changes to get you to your destination on time. If your flight is delayed by weather or even technical difficulties, the airline's only obligation is to make sure you get to your destination eventually. But if you book your air through the cruise line's premium air program they will make sure you get to the ship. This is not to say they will pay all of the resulting fees or differences if you have to fly to the first port of call, that is your responsibility, but they will do the work of changing the flights and cover some change or cancellation fees - depending on the program you select.
I didn't say anything about guaranteeing the first port of call, etc. I didn't say it will always be feasible, I didn't say "at no added cost." I just said they will find a way to get you to the ship - that is what they promise - even if it is going to cost you $10,000 and gets you there on day 7. This is what the programs promise - that will find a way to get you to the ship but YOU have to pay the fees. If they did not offer this it would not be worth paying any extra fee.
If you choose to pay full fare for unrestricted air tickets you still have to pay the difference if you change your destination, you just don't pay the change fee. So, I don't get your point about having 'the airlines on your side."
The airlines don't care who you are or where you bought your ticket - they only care what kind of ticket you bought.