Why should anyone create software just so you can have it for free? You're not entitled to open source software, or the goodwill of others. If they decided that they didn't want to continue running their product, they can choose to shut it down.
This is exactly the same as Sparrow, TextMate, etc. None of these companies owe you anything to where they should be required, or even expected, to open source their work.
This is exactly the same as Sparrow, TextMate, etc. None of these companies owe you anything to where they should be required, or even expected, to open source their work.