Distribution is Infrastructure, hence why the national grid is the national grid, and should remain so. Generation is a bulk commodity, and having bulk commodities in the hands of government alone is not a good idea. If the UK government were the sole body with the right to generate electricity we would probably still be a coal powered nation.

You bring up food, but would you really want all farms nationalised? A total government monopoly on food production is the ideal in your mind?

If something is 'too big to fail', then it should be mixed, with both public options and private. Two points of failure are better than one. This way you do not need to bailout the private sector unquestioningly at every market scare, nor does the entire country collapse after a few years of government malice/incompetence. Imagine how much more damage the Tories would do if they had control of all 'Essentials to modern life and civilization' instead of just the relatively small slice currently done by government in the UK.