The key failing of breaking up a large organisation and selling off the parts is that some bits generate money and some cost money... While they remain as one they offset each other. However, breaking it up and selling it off means the benefits of the good parts generate profit for the new...
The staff at the London Bridge "excess fares" window are WELL AWARE of how sh*t portslade is. Have had to buy tickets from there regularly and they know as soon as a queue starts to form a Portslade train has arrived - seems to be an in-joke for them!
Or indeed the "improvements" to London Bridge itself... Otherwise disguised as the installation of 20-30 retail outlets serving little/no useful purpose and the building of a two-tier platform/concourse designed by someone who has never seen a 12-carrriage train empty and the entire passenger...