These things always go in circles. People like the idea of microfranchises, like one for Devon/Cornwall... but then they want one unified network across a region... then they complain about a lack of competition... then they complain about unnecessary competition (when TOCs are fighting for the same market)... whatever we currently have, the grass always looks greener elsewhere - one year we should be merging "local" and "InterCity" services (so that we can hide the subsidies required for the quieter branches), the next we should free up different types of service into different franchises so that management can focus on one thing. Plus ca change...
One thing I would say is that we should be careful when wishing private companies take over the infrastructure and we should have some kind of plan for the viability of long distance routes that would pass over different "regions" - e.g. if you are the company running tracks and trains from Sheffield to Chesterfield then what's your incentive to give plum paths to "foreign" routes like Aberdeen - Penzance or Liverpool - Norwich - or to regulate those trains to keep them to time? Fragmentation can be a slippery slope...
the extinction of the unified, consistent InterCity brand and network is one of the worst things to have come about through privatisation
I'm not sure that InterCity was quite as unified/consistent as it's now remembered as being.
- 158s were InterCity (running routes like Glasgow/ Edinburgh - WCML - Manchester and other CrossCountry routes down to Portsmouth etc)
- 73s were InterCity (Gatwick Express)
- Mk2s were InterCity
Routes from London to cities like Norwich/ Oxford didn't qualify as InterCity, nor did routes between like Edinburgh - Glasgow Queen Street or Bristol - Cardiff (but the one from London to Gatwick Airport did).
Some trains ran InterCity services without carrying the branding/livery (like the 158s I've mentioned), some trains ran around in what most passengers would have assumed was InterCity livery (e.g. the "Mainline" 37s).
We all complain about inconsistencies and differences between TOCs today but it was ever thus - e.g. the ECML getting more in the way of First Class facilities/ meals than the parallel MML did.
Don't get me wrong - BR were great at branding and marketing - probably much better at those tasks than they were at actually running trains most of the time - but I think that the InterCity brand/network was more complicated/diverse than people now remember it.