This has been a thread of contention numerous times on FT. It has almost become as legendary as the "knee defender" thread(s).

Personally yes. I believe one of the ME3 carriers currently offers this.

Last week I flew BA CW and the couple behind me had two young children that howled and screamed just about the entire 8 hours all but making any relaxation null and void. I was incensed. The kids were throwing temper tantrums left and right. I'd be happy with them, followed by the complacent idiot parents down below in the hold.

On the other hand on the return AA flight in business from LHR-ORD there was a family of 5 seated behind me and the 3 boys from I'd say 7-12 in age were polite and quiet the entire time. It's a mixed bag I guess.