Should train companies assign one or more carriages to 'families only' for long distance journeys?

They have (or had) smoking carriages for trains that do long distance journeys (Virgin, GNER, Midland Mainline, First great Western etc) - should they perhaps consider including a 'family carriage' for people with young children?

i had to spend 5 hours on a train from London to Glasgow surrounded by mothers with small screaming, crying children - it really wasn't pleasant. I nearly smacked one of the little brats when he came to me with jam-covered fingers and trying to climb on my lap.

Would anyone else prefer if all these parents and children were put in a separate carriage away from the rest of us who just want to be left in peace and not covered in jam and dribble? Most of these trains have a silent carriage - maybe they need a noisy carriage too?
Additional Details
Yes I agree more parents should control their kids, although this is difficult when they're throwing a proper tantrum.

But this is a more socially acceptable solution to the problem - personally I think all kids should be sedated and locked in a box for the duration of long journeys, but I don't think many people would be too keen on that idea!