"Private companies are more efficient" is one of those things that's been said often enough that it becomes a "truth".

This obviously doesn't pan out when you've got a monopoly or captive audience. Around me we have a choice of energy retailers, so we get to deal with the "efficiency" of several competing bureaucracies instead of the "bloated" government one.

Politicians love it because it abstracts them from any accountability to the people, even our left wing parties are pro-privatization these days.