Also take into account the additional wear and tear (and reduced acceleration) caused by lumping around a damn great big diesel engine and generator set when its under the wires.
We certainly like to do things "differently" in the UK. In all my 30 odd years working in continental Europe, I've only ever come across one unelectrified line.
SNCF has several bi-mode routes and seems to be keen on the Alstom Polyvalent design (diesel engines on the roof).
Paris-Troyes-Belfort is one, but they are also extending the wires to Troyes at the same time so it will be a mixed fleet of EMU and bi-mode.
Germany still has several pockets of diesel working, but it has a rolling wiring programme so the diesel areas will get smaller.
They are going for hydrogen trains in the north (also an Alstom Desiro design).
Denmark has a major wiring programme on the go, and has ordered straight EMUs rather than bi-modes.
Italy has gone for bi-modes in the far south-east and north-west.
Spain has its all-singing. all-dancing class 730 which is a bi-mode version of the class 130 dual gauge, dual voltage high-speed tilting train (Talgo/Bombardier design).
It runs on standard gauge high-speed 25kV AC lines at 250 km/h , and also on classic Iberian gauge routes, not all of which are 3kV DC electrified.
But its sphere of operation is diminishing as more high-speed lines open and more of the classic network is wired.