So it is okay to ditch 10 year old class 379's? Or class 332 Heathrow Express units also after 10 years, just because they apparently cannot be used anywhere else?
As far as I understood it, the 332s were owned by Heathrow Airport Holdings and were completely knackered by the time they were withdrawn. Therefore, not within the financial remit of the DfT; so HAH could do what they wanted with them. It is the same scenario when it came to the “uproar” about the 360/2s being scrapped and how they could have apparently been utilised for service elsewhere on the network (eg to supplement EMR’s Connect operation).
Nevertheless, even if the 332s were under the DfT’s remit, if the trains really were that knackered, they couldn’t have gone anywhere else (apart from the East Midlands, seemingly the perennial dumping ground for knackered stock

).
Fundamentally, though, there is a looming headache about replacing the 15x fleets across the rail network as a whole, SWR’s 158/159s included. The 15x as a whole probably have got another 10-15 years left in them; so something needs to be decided
relatively soon (but no doubt it’ll be left until the last minute!).