Yeah, as said elsewhere, communication in that case is not very good. All we know is beta is not coming for Linux and release dates for specific platforms will be announced some time in the future.
No technical explanation, no clear comittment. I would say Inlesco is perfectly right when saying that WH can get away with it. We're not in a position to put any pressure on them (and at the current point that also would seem counterproductive).
Of course, for all we know (and we know next to nothing), it may be an issue that is not under WHes control. Whatever it is, letting us backers know would be the the right thing to do, even if it would not change the current situation. At least we would no longer hang in limbo.
Btw., I also agree that Linux is a growing market, and it is certainly a worthwhile target, even though the absolute numbers right now are still low. Sooner or later, investment in the required technology will pay off. Better to be at the forefront when it comes to gaming on Linux than being one amongst many when the rush starts in earnest .