I did comment that the LPTB border was drawn up by busmen, for their mutual benefit. Places like High Wycombe had one busman running into it from one direction, and another from a different direction: as it was where they both wanted to run to, that's where they agreed the boundary should be. And in the days when it was all paid for by passengers paying individual fares, with a service licensing system that meant service patterns were pretty stable, facilitating crude co-ordination, it didn't matter that much.
But things have changed: service patterns are less stable, making co-ordination more difficult, and fare/ticket systems are based on zonal 'ride at will' travel cards (of one sort or another), with significant payments from general public (government) funds, it matters far more.
So where do you put boundaries? If you're not going to have them splitting places like High Wycombe in two (or more) - which I agree is undesirable - how do you deal with the fact that people want to travel to/from such places in multiple directions?
What are the implications of the logical conclusion, that the whole country has to be in one area, one scheme...?