The problem with nationalised industries is that they don't make a profit.
Obviously that is only a problem for the people that want to make a profit. The rest of us recognise that it would be better for a service to run that benefits end users rather than shareholders. Education, Healthcare, Fire Service, Police, road network etc don't make a profit. They are public services and the country runs better when all of those things are working well. Better infrastructure, healthier people, educated people, safe people are happier and more productive and it is better for all of the people in the economy. Train services/public transport don't have to make a profit. They have to offer something that makes all the other things we do easier which increases investment and productivity for the economy.