Why I <3 Trains...

To honest what are the train companies meant to do?

The train network is operating at nearly full capacity.
The possibility of an extra carriage for bike would be nice but most people would rather have some more seats so they did not have to stand up for 90 min.
Most train lines outside of London don't make a profit and the London lines tend to be used to subsidies the smaller less popular lines.

The crowding on the trains could be elevated slightly by expansion in the network (and it need it) but:

1. In cities finding space for these lines would be dam near impossible, tunnels are prohibitively expensive.
   
2. England is a crowded country, especially the south. Just like for the road network, I expect there exists a critical density of population for which exceeding capacity of the network is inevitable for a given movement rate of the population. Here I am using "movement rate" as a term to describe / quantify the need / want of a population to transport them selfs. This "movement rate" term would not be isotropic as clearly more people head into town than head out.
   
   

The only way to truly sort out the transport system is to reduce the need / want of the population to move.