I had an inside view of the process as an American consultant to BRB in setting up the ROSCO's. While part of the political motivation was ideological, a lot also had to do with Parliament's frustration with dealing with the BR bureaucracy. BR was technically very sophisticated and tended to justify ever increasing subsidies with endless techno speak. The technical sophistication also led to a very bespoke, overly complex operation that was both unreliable and had few economies of scale. While part of the theory behind the fragmentation was to create competition, it also was intended to create more transparency (and give Parliament more control over where the money went). I am probably prejudiced, but I think the ROSCO's made some sense and have done ok. But the TOC's were way too fragmented. And trying to privatize infrastructure was a disaster from the git go. And it was all done in a hurry because the Tories figured they would loose the next election. So the Tories replaced a known terror with an unknown terror. The best that can be said for the process is it has created an opportunity to rebuild (fix) the system, and what exists today (28 years later) may well be somewhat better than what existed before. But doing so has cost the British taxpayers a tonne of money. FWIW.

JBWX