"Evidently you don't remember what an execrable mess the railways were under state ownership. "
That has a lot to do with them having been an execrable mess before they were nationalised and management of those private companies continuing to be regionalised management of BR, complete with the rivalries being perpetuated.
There was so much infighting within BR that it's a wonder anything happened at all. It and British Leyland are not good examples of how to amalgamate things.