I attend the local Rail User Group meetings, and there was correspondence from the DfT which said that it was VT who said that it would be impossible to stop any additional services at Nuneaton, and that VT was free to propose such additional stops if it wished. The DfT's position was that it's franchise stopping patterns was only a minimum requirement.
If you want to understand VT's motivation, look at its Saturday southbound LIV-EUS service at 0848 which does have time to call at Nuneaton. This same service on weekdays does not have time to call at Nuneaton which VT told us was due to path availability and to improve reliability. However, no evidence of this has ever been forthcoming. And of course, the obvious explanation would be that, were this fast service to stop at Nuneaton on weekdays, it would be off-peak and might cause some passengers to switch from the earlier fast peak services.
This pretty much encapsulates all that is wrong with rail privatisation, where passenger inconvenience is secondary to profit. Make no mistake, VT is as much to blame as the inept DfT.