I think for a commuter train, FC is purely for the extra chance of getting a seat at peak times. For that to work, there needs to be some level of enforcement to stop people just upgrading themselves. It IS different to Intercity because you can't upgrade - although one day that might be possible by having a way to tap in with your smartcard and be charged a flat-rate fee. For enforcement, you go for those who didn't and make sure the pad won't accept tap-ins once an RPI has boarded!
I disagree that FC should be axed, although I do get the argument, simply because people buying a FC ticket (however that's funded, by themselves or expenses - who cares!) pay a LOT more and that can subsidise standard tickets to a degree.
As we get newer rolling stock, I'm sure the first class offering will improve with nicer seats, a bigger table and free Wi-Fi etc - but still lacking a trolley service or buffet. Of course, standard class will also improve considerably too.
Perhaps FC on a suburban commuter service will one day be an ordinary standard class layout (thus fitting in more people) but be sold at a premium purely to get that seat?
