The irony of those that criticise the Major government for privatising because of ideology is that promoting nationalisation as a magic solution is just as ideological.
Too many people forget that our rail system was built by private money for profit and operated privately for the first 100+ years. State ownership was a period of service reductions and vast waste. With more irony, the ‘golden age’ of BR mentioned above was when it was restructured to operate like a business rather than a public service.
As with all public services/industries, what matters is how it’s run rather than who runs it.
Whilst I agree with your comments that it is how services are run and that some of the time while under state ownership there was service reductions. However, you have had service reductions with the privatised TOC's, in some cases due to lack of staff training and staff being available, plus TOC's needing to cut costs. Which I will probably be corrected, was the same issues at time under BR when there was service reductions, was it not?
Maybe because things are developed more on computers, but I believe things are also tested elsewhere outside of the UK now, such that you do not have the test trains such as the APT-E or the HST test train anymore running on the UK rails as part of development plans for the next set of trains to be built. Yes, in more recent years you have had class 8xx trains out on test, but that is as Production trains, rather than a test train to test the technology out first, before it is provided in a train to be used with the public. maybe in 30 - 40 years time a class 8xx will be provided to the National Railway Museum?