I doubt that there's that much interplay between the pricing structures of the train and plane on most of those routes, but, as a semi-regular user of East Coast, it is worrying, and a bit baffling, that a service that has worked relatively well for the past five years is being dropped.
I also wonder why it is that the government is quite happy for the UK railway services to be state owned as long as that state is not the UK. Was there never a chance that Directly Operated Railways could grow and compete with the likes of Abellio, Deutche Bahn, and Keolis?