Locomotives no more - why?

[route:oxford]

Crumple zones do not need to be the length of a whole loco or DVT. Which ever way you look at it a loco and DVT use up passenger space that MUs can use quite nicely. Not sure what you mean by adding redundancy?

The crumple zone on a DEMU, such as a Voyager (at both ends) takes up a considerable amount of potential passenger accommodation.

Redundancy, this gives the opportunity to "get home" when one loco fails. ie an HST can get there a little more slowly if one power car fails.