WSMR was always going to be a slim operation, even before any recession - employing fifty five people whilst running three return trips a day may have meant high passenger satisfaction scores (based on the level of attention that staff could afford to give passengers) but not a great business model.
It'd have struggled even if Virgin had sat back and done nothing.
It may have been able to have been more viable if Virgin had allowed it to call at some of the stations that they called at. As it was it was only catering for passengers to London and not passengers to say Birmingham. As such when (whoever runs the new franchise starts the service) it runs it will attract more passengers because it will call at more places and therefore be viable (even without the savings of it being part of a larger operation)