When I first started working at LGW I think the airport was handling around 12 million pax per annum (1976). The dedicated train link didn't exist and the whole experience of travelling by train to/from LGW in peak periods was very unpleasant. Bags were strewn whereevr the owner could put them and if there had been an incident an emergency evacuation would have been almost impossible.
As the Airport grew the BAA lobbied to get dedicated trains for the service between LGW and Victoria. The service was restricted to 3 paths an hour and then grew to the current 4 an hour. Off peak the schedule was reduced. The standard of comfort and convenience offered to the commuter and LGW pax was greatly improved by their segregation on seperate trains.
Now with the airport handling 30 million pax per annum some one thinks it will be a good idea to remove the service. I have to admit that I cannot see the logic in this move. The number of additional paths will not be greatly increased due to Terminal restrictions at Victoria and Brighton, whereas LGW has had a couple of realignments to make it efficient.
As another poster has pointed out already, this current proposal will not help the peak time situation one Iota for the LGW passenger, and I doubt commuters will appreciate the LGW passengers pushing past with their heavy and oversize baggage, banging knee caps and ripping suits.
One other point which is relevant is that pax baggage is now far larger and heavier than it was back in the late 70's when they had to carry it. Now that pax can wheel their bags it is far larger and heavier.