No, because third party alternatives like AirParrot or Beamer work just as well and without the hardware restriction.

They may work, but they don't work just as well.

Oh yes, you're right. They don't work just as well, they work better.

AirParrot has additional features like sending only one specific application window to the ATV and control over quality.

Beamer lets you seamlessly stream any kind of movie format you want and also gives control over subtitles.

Both work all the way back on 10.6. I don't suppose you could give me any advantages of Apple-branded AirPlay Mirroring huh?

The point of Quick Sync is to offload video encoding to specialized hardware, which reduces CPU usage. A quick Google search confirms that AirParrot uses a lot of CPU, which hurts the user experience. I won't opine on whether this is worth dropping the feature (and of course an application could be designed to use Quick Sync if available and fall back to the CPU otherwise; would be nice if OS X exposed this as a public API, although I think it's not hard to get at anyway), but there certainly is an advantage.

This has been discussed before.

http://arstechnica.com/apple/2012/07/mountain-lion-airplay-m...

Tried Airparrot - quality was terrible in comparison.

Year old review (software improves) and you may have missed this: http://cdn.arstechnica.net//wp-content/uploads/2012/07/Scree...

Too much work for my mom, thanks.

I get the impression you've never actually used the software.

I think it is more that Apple didn't want to implement and maintain two different solutions for the same problem.