The bottom line is that national rail train operating in the UK is now just a commercial business' and given the lack of real choice that the majority of London's travellers have, the operators will do whatever they can get away with within the rules of their franchise contract to maximise their profits. So if Bombardier or Siemens offer seats with less padding than some passengers want for a lower operator cost, the procuring and operating TOCs will go for them.
It was a commercial business prior to 1948 and that resulted in seats that passengers visiting the Bluebell railway riding in Bulleid stock now regaularly think are first class because they are so comfortable.
However, I do think that the franchise system does encourage, short term, cheap as possible thinking of the type you describe.
The problem with that strategy is that people do have a choice, and that is now starting to include the peak hour travellers, due to the creeping spreading of working at home, as broadband systems get fast enough to support computers communicating at home with office servers as fast as they do in the office, plus the collapse in weight of laptops means taking it home is far less of a chore. The recent spread of unlimited broadband packages and shift in telephone billing toward fixed fee rather than usage based charges is also encouraging this.
Just as the invention of the Telephone helped to for the London and Blackwall railway as shipping agents could phone the docks rather than have to travel there, high speed broadband enabling working from home will before too long impact the commuter franchises.
Obviously the traffic won't disappear altogether but there will be a shift to less trips and trips made in off peak hours instead of during the peak (when of course driving is a lot more feasible)
The recent fall in Petrol Prices and completion of the rebuilding of the M1 and M25 areas paralleling the Thameslink route may also result in pax deciding to drive to Stanmore, High Barnet or Cockfosters if the seats are uncomfortable.
I have an uncomfortable feeling that technology is going to put a stop to the year on year pax numbers quite soon.
