I'm not sure what you mean by time-limited promotion. If you go to the kickstarter campaign (which evidently just closed), you will be able sign up to pre-order the unit at the same price as the kickstarter campaign. Perhaps it was originally $35, and the article and other similar articles shamed them into reducing the prices back to $9, I dunno.
That is the nature of some kickstarter campaigns, where the initial backers kick in money, and if the project is successful you get the doodad cheaper than the eventual retail project will cost. You are paying for initial development. On the other hand, the project might not be successful, and the initial backers are left high and dry. Where a lot of people get hung up with kickstarter, is thinking it is a normal retail store with finished products, where as I tend to see it as a tip jar to help fund the next product, and you get some rewards if successful (and you might get a pile of junk).
While there might be other areas where they might have been problematical in terms of their promises (the GPL violations that were mentioned for instance, and the original high price of shipping), I don't think it is a problem in offering a product to initial backers for a lower price and then when you go through the normal retail pipeline, the price is higher. After all, when you go the full retail route, it becomes a regular job where people expect to be paid regular wages, and not something done in a garage to get the orders out. And in the retail route, you had additional middlemen like distributors.
The triggertrap Ada that I mentioned before had the problem that they seriously mis-calcuated what the true costs were to make it as a product. They could build and sell it for $150, but the market for those type of devices might have been $50 per unit. They had to go through the issue of trying to refund what money they could.
Remember, the Teensy 3.0 was originally a kickstarter campaign, and it sold for $22 at the low end, including US postage. If you buy a Teensy 3.0 from PJRC right now, it is $19, and shipping is $7.95 ($26.95). If I go over to Micro Center and order a 3.1 with standard shipping, it would be $25.98. Now, since I have two stores locally (MicroCenter and You-do-it) that sell Teensy's, I can avoid the shipping charge if I drive to the store, but in the general case, you can't avoid it.
As I said earlier, once you price things out to include display output, etc., for me, it makes more sense to stay with Raspberry Pi (particularly since the main thing I do with Pi's is attach the camera, which is not yet an option for this other board). This is particularly true, since I can go out now and buy a new Pi, with lots of different options for hats, etc. and I don't have to wait until they finally ship.
FWIW, I bought one of the original Pi's in their roll-out, and then let it sit on the shelf for about 3 years, until I came up with a use for it. By the time I looked at the Pi again, the infrastructure had blossomed. Hopefully the infrastructure for the unit will also blossom. However, I suspect that by now the Pi has become the dominant force, and Beagle Bone Black, pcDunio, banana pi, etc. are niche players.