Dude, I'm advocating an apology and the offer of full refunds and even I think you're going too far!
What you say may have some element of truth but it's almost impossible to quantify so the absolute best FD could do is offer refunds of the actual amounts.
Wherever money is concerned there are laws and financial recourse for actions taken. Offering a refund is a cheap way out and FD knows it. They will make lots of money off this thanks to people who invested in the development of the game. I am saying that they need to do a lot more for their upset long term backers who they have badly let down. Thank goodness for Exec Prod Michael posting as at least he is contributing to this thread.
FD as a company are liable for their decisions, taking money albeit with the best intentions to develop a game with lots of great sounding promises and delivering a game where parts promised are missing or swapped out is wrong, in-game features should never have a promise attached, a 'we will try our best to' or 'we will aim to make that work' should have been used instead of absolute guaranteed promises which ended up not being guaranteed. This has led to potentially a nasty legal problem. Terms such as obtaining money by deception and fraud have been bandied around and although very harsh those terms do apply.
FD need to step up and get their PR department into overdrive preferably with their legal guys advising them this time..., they also need to placate the current testers (i.e. us) and a few extra ships and reduced insurance costs are no alternative to those who are upset at no offline mode.
This whole thing feels like they have known for months and tried to sneak in the announcement hoping no-one would notice and I think that is the reason for a lot of upset. If FD had been up front and given prior notice letting us know months ago that it was looking uncertain then people would at least have been more prepared. A few weeks before launch has clearly left people reeling.