Remember, though, that in a business, efficiency is much less important than overall cost. There's been quite a bit of re-evaluation of the Pennsylvania Railroad's Q2 and T1 steam locomotives over the past 10 years or so, and opinion is moving in the direction that they were, in fact, among the best, most powerful, and most efficient ever built. But within a couple of years, the PRR nevertheless realized what every other railroad came to understand, that steam locomotives were so expensive to operate that a wholesale conversion to diesel was necessary, as quickly as they could make it.

Not only that, but the PRR's managers also had the choice of dieselizing or extending catenary (They knew they couldn't do both). They opted to dieselize, despite having one of the best electric designs ever and a for that time state of the art plant. (Even that, though, was subsidized by the New Deal.)

The fact is that European electrification was always undertaken as a state subsidized project, and from the 1950s onward was financed by the lessened need for Western European and Japanese governments to spend on defense. It was less an "investment" than a windfall benefit of the US nuclear umbrella. A lot of the pro-electrification discussion here implicitly recognizes the lack of return on electrification -- but let's face it, in paces like Germany or Japan, the electrification has never provided any return on investment. Yes, if you get a tax-supported rail agency that can gold plate its specs, you can electrify.