Adobe might be focusing a little too much on the mobile / smartphone market, to the point of sacrificing or re-allocating developer resources away from the desktops and targeting smartphones instead. They have a massive installed base on desktops and they service a large and steady market in the enterprise sector with Photoshop and the Flash content creation platform (and AIR). If they are going to remove support from the free applications that the content creators depend on to run their content, this will hurt the content creators, because they get fewer users / customers.
If anyone should be upset about this move, it's not the casual user who doesn't pay anything for Adobe AIR. It should be the people who shelled out literally thousands of dollars to buy the expensive content creation software that lets you write AIR apps. Because a piece of their market share just evaporated. And maybe it's not that case that all AIR apps have the same market share as the overall AIR downloads: perhaps certain apps are extremely popular on non-Windows platforms. I wonder how many Pandora Plus users run Linux? I'd bet you that out of all the Pandora Plus (AIR app) users, it's significantly more than 5% running Linux, just because of the nature of the software.
Hypothetically, if Phoronix had their own AIR app, you'd see some 50% or more of its users running Linux, BSD, or Mac. For a general purpose platform like AIR, the overall download statistics mean nothing about the user-base composition of each individual application running on the platform. So it's very possible that Adobe just screwed over some app developers who depend on a significant Linux user base (even if, indeed, their total user count is small). That would make me legitimately angry after spending so much money on their content creation tools.