And it's awful everywhere.
One station that has been ruined by it is Inverness. Before the gateline was installed, a civilised, one-abreast queue formed for each departure, snaking around the concourse. Now it is yet another scrum.
I'd love to see one of the disability or elderly campaigners challenge it on accessibility grounds. The only people who gain from it are fit young people.
I'd like to know what you would change exactly, given that a) people will arrive at the station before their service is ready, b) the need to clean the train, prepare the turnaround, the crew to be ready, reservations to be loaded and c) not taking into account any delays, d) the fact the platform can only be announced in one go (i.e not in stages), e) there is not seat control (i.e "coaches A-C board now, D-F please wait").
People are correct Euston does have more space on platforms, but pyschologically many don't like waiting on concourse, their being told their platform only to then wait around before they can actually board their train. This might be one where regular travellers and less frequent travellers differ (much like this forum's attitude to announcements).