That's not the customer's problem. If I promise offline mode and design the game so that offline is impractical to implement and end up not being able to deliver the promised feature, I made a mistake and I should take full responsibility for it.
"Taking responsibility" should not end with giving an apology, no matter how appreciated.
I fully agree with you and am myself annoyed enough by this decision to never buy another thing developed by Frontier and that is a promise I will keep. Because I feel that droping off-line mode was not some little thing and it may well have not got enough funding on Kick-starter if they hadn't promised that I remember well how important it was to many who origionally backed this.
I was just explaining why I think they have made a decision that is tearing their player community apart, alienating people from doing business with them in future and dragging their companies reputation through the mud in the press. I do not argue that any of these conseqences are not fully deserved and that they have anyone to blame for any damage to their reputation and future business than themselves.
They promised off-line during the kickstarter and beyond in pre-sale and a month before release they have pulled the plug on it. To be clear to me that is not and will never be exceptable, to abandon off-line so late in the day shows it was never taken seriously as a requirement in the design and hence they never really cared about having to deliver it regardless of any promises made to get more money early on, that's unethical period.