Indeed you could, but (ignoring abstraction issues) would it make money with a SVR to London of at least the Peterborough fare of £50 (OK you could charge a bit more but how much?). Bear in mind that there is very little intermediate traffic, so you are essentially running for 80 miles to tap into the Doncaster(and north)-London market where there are already 2 OA operators.
LNWR works as it does because the WCML upgrade went wrong, Virgin essentially withdrew from Trent Valley and a franchised service was required to give Nuneaton etc a tolerably good London service. And as a franchised service, they couldn't be stopped from undercutting Virgin, just like GN and Peterborough.
Full marks to Silverlink or whoever it was for spotting a business opportunity, but it would never have happened without the need to serve the TV stations.
The equivalent would be to hand Retford, Newark and Grantham over completely (or nearly completely) to GN and run a semifast with 387s (or...), calling at Huntingdon and St Neots or Biggleswade. And you'd have to go half-hourly as far as Newark, because that's what they get currently. I can see that being popular - not.
I'm not sure I agree entirely with that assertion. Stops like Grantham and Newark generate a decent amount of traffic in themselves.
If you had this as a semi-fast limited stop from Peterborough, it might have the added benefit of drawing some Peterborough passengers away from IC services.
