If everyone asks for a refund, won't they wind up losing some fraction of one year's worth of revenue?

They'll be slightly less rich, but still considerably more rich than most of us.

You seem to know a lot about the economics of being an indie app developer and consulting firm. You should share more about how much cash they must be rolling in.

Too bad? The idea that we should treat companies that stop longer providing a product as charities deserving of free money is a bit silly.

Twitterific built their business on something that we often acknowledge here as being very shaky: the whim of a third-party platform. If the company hasn't considered and prepared for the scenario where that third-party platform completely cuts off your access, that's irresponsible as a business owner.