Apple is certainly not perfect, they've made mistakes (MobileMe, Ping, etc.) and they've had huge successes (iPod, iPhone, iPad, MacBook Air/Pro, etc.). But in this case, AirPlay is NOT a crucial feature of the OS. It's not something fundamental like web browsing, music/video playback or connectivity. Besides, in most scenarios involving AirPlay, your computer is relatively close to the HDTV it's streaming to anyway. AirPlay just allows you to cut the HDMI cable from computer to TV. If you really want to, you can hook up the computer to the TV using HDMI, VGA or DVI depending on what your TV supports. The best part of this method is that it doesn't require any kind of video stream/encode, QuickSync or any of that. Most likely, you'll get higher FPS through a cable than AirPlay. Also, AirPlay requires an Apple TV. That's a separate hardware purchase. I also remember Intel's WiDi technology only worked if you had dongles and adapters all over the place. The fact is, most people don't have Apple TVs or WiDi dongles/adapters. Most people don't NEED or USE AirPlay and AirPlay-like functionality on a daily basis. Your $3000 MBP or $5000 MP just can't wirelessly send a screencast to your HDTV. Is that the main thing you do on that computer? I seriously doubt the answer is yes. Seriously, you can't get everything in a new OS. In Windows 7, there's support for all kinds of features that require compliment hardware. Same with Linux. And practically every OS out there.
If the main functionality of your computer regardless of how much it originally cost is to wireless mirror the display to a HDTV, then I guess you are right to be mad. But Apple didn't take away any EXISTING functionality. You just didn't get a new one. Not a bunch of new ones, JUST ONE FEATURE. GET OVER YOURSELVES. Your computer still work EXACTLY like it did the day you bought it. For $20, you get a bunch of new features. Be thankful for what YOU DO GET instead of what YOU DID NOT GET. Why? Because there IS ALWAYS something you did not get. ALWAYS. Thanksgiving should come early for people like Moonloop. Maybe all year round.