I've genuinely never considered being away from families part of booking F / J... because I've regularly seen families in F / J.
Maybe I'm on the wrong flights?
Like I said before, when airlines state that certain cabins are childless, that's when you can rightfully expect not to have to deal with them.
Edit - I'm actually starting to wonder if it's the fact that I don't have kids that means I'm not so easily offended by their presence!