Airplay is a good backup solution. But it's a hassle to use compared to being able to control everything from the TV.
In theory, yes it obviates the need for jail breaking. In practice, you (or, more likely, the rest of your family) are not going to want to get up from the couch to go over to the computer and start up the movie then click on Airplay mirroring every time you want to watch something. And then have to go back to the computer to pause, rewind, remove a notification that pops up on the screen, disable audio from your e-mail dings, etc. Yes there are elaborate remote control solutions using your smartphone, but #1: that is more of a hassle than using a push-button remote and #2: think about that: you are tasking your smartphone to task your computer to transmit an image over your wireless router to your Apple TV. Wouldn't it be easier to just control everything from a universal (non-touchscreen) remote from the couch?
I'm telling you. I have a jailbroken ATV and airplay mirroring. I almost never use mirroring because it's a hassle. Even on my ATV3 (obviously non-jailbroken), I rarely use Airplay mirroring. And if it's too much of a hassle for me, it definitely is for my wife.
