I must have been dreaming then when I did it myself...or when there was a thread on this very site about it when FaceTime was first introduced.
Believe me...it's the next thing that stupid people will fight over.
"I'm a blah blah blah important attorney and have to work on the plane."
I personally don't see an issue with not using my device or have headphones on during the safety instructions (that I have heard 1,000+ times), but letting people start to talk on their phones or FaceTime over the wifi system will cause an uproar....and I travel for business all the time.
Plane time is sleepy time for me...