Because then if the first class coaches are at the front and back there would be no wheelchair access to the train.
Just goes to show the stupidity of cobbling two 5 car
DMUs▸ together and calling it a 10 car train ! Did no one think of this problem ?
Careful now, I have been told off for calling them DMUs. Even the MD insists that they are electric trains that can also use diesel power.
DMU is considered a negative term that might in passengers minds be associated with shorter trains that lack buffets, padded seats, luggage space and other facilities found on inter-city trains.
The sort of thing that used to be confined to branch lines or secondary routes, but these days they are infesting main lines.