When people want renationalisation, they need to take heed of the absolute foul ups in governmental organisations that were never privatised, such as NHS and HMRC who are prime examples of public sector waste and incompetence.
There's been no real improvement in the train operating firms that are now back under government control, such as Northern Rail, who remain as useless as ever with constant cancellations, short trains, etc. despite being back under government control for the last six years! Plenty of time for improvements to start to be seen, but no, no improvements at all.