You have raised an interesting point that I hope those of us around here who follow affairs of the freight railroad industry (that's 90% of it) will choose to discuss.
First, let it be noted as a disclaimer, I am a former employee of the only North American road that electrified lines primarily to handle freight traffic - the MILW ('70-'81). But after reviewing the immediately linked article, I must agree (and that my road went on a folly).
Of interest are two recent encounters I have had Overseas. One was with an English speaking gal with Fedex in Warsaw. She knew Fedex made use of rail in the US, and asked me why weren't railroads electrified to the extent they are "over here"?
I showed her some photos of US trains over which she was astounded and I said they generate their electric power as they go. I also added "could your transmission systems provide that much power to ONE train"?
She wasn't sure, but neither am I (Mr. Nas, you out there?).
I further noted that what electrification there is over here is solely used by passenger trains, and outside of the electrified Boston-Washington route, there are simply not enough of them anywhere to justify the "first" (capital) cost of such.
My second encounter was this past August with an educated (London School of Economics) gal who was with the Ugandan Transportation Ministry. We talked about freight transportation. I showed her photos (on my phone) of freight trains over here. Same reaction; why don't you electrify? Here I was evasive as I didn't want to "talk down" to a member of a Third World country's government.