I don't see why the Overground could not now run the Clapham Junction to Watford services - how many extra units would they need?
Eh? Have you ever dealt with TfL? They don't just do trains, but bring a whole massive service concept with them: platforms to have Roundels, drivers to be trained TfL standards, platform at WFJ to be fully accessible, etc. All good stuff from a customer viewpoint but involves a lot more than shunting fleets around. And, as another post reminds us, the WFJ trains would have to run on a real main line, not just the DC lines, so can you imagine the preparation that the staff, managers and high-ups would need to be able to cope with that?
More seriously, the GTW to MKC service has been a poor relation ever since it began and this latest throw of the dice seems to indicate that it's now practically on the way out altogether. Despite going for c. 20 years (thanks, Connex), it's not really been relieable enough (including how far it runs from year to year) to build up a regular market for what otherwise would should be quite a handy service, particuarly going via Westfield and Kensington (now cut off from the tube once again...) The cutback to start it from CLJ some years ago also seemed to eat into traffic.
When we look back on this sorry tale, it will probably feel that it is a classic triumph of the railway's operations functions over its commercial colleagues (hardly the only such example....) Running through unfriendly territory north of West London Line Jnc and barely tolerated in its own 3rd rail homeland, it was always being fingered for holding back PPM on both sides of the Thames. Really? It was (sorry, I should say 'is') only 1tph!!!
