I loved the old DMU's with a view out to the front, and recently I rode on one on a preserved railway and it reminded me how nice it is to watch the track ahead.
But actually only 3 or 4 people on the train get a good view of the line ahead - those in the front row behind the cab, except for someone sitting directly behind the driver! And perhaps those in next the couple of rows get something of a view too, if the seats have low backs, as on most DMU's.
I can understand that the driver might not like people staring at the back of his neck, so it's fair enough to block the view from behind his seat, but on the right-hand side surely it would be nice to allow a view ahead - assuming the DMU isn't fitted with corridor cabs like many are today!