It's not so much the market forces as the way the privatisation was structured, and the perverse incentives that were created. The tube is a good example - there are multiple maintenance firms, line management firms, Transport for London, the unions, etc. All of them have competing agendas, which doesn't fit well when they are providing one product. I would be happier with a public monopoly than the current situation, and would accept a private monopoly instead of both, contingent on them getting the incentives right.