On my return trip a week later (today) I opted for the connection that needed no other transfers and a reserved table seat. So at 09:26 I am waiting at the (non-staffed) Penmere Platform for a train... that is canceled... Fortunately I could sit at (unreserved) table seats on both connecting trains and I am now 30 minutes away from Bristol Temple Meads. Then only a bus ride away from the airport.
The British and the Dutch rail system appear to have more than one thing in common. Privatized and delays. And maybe they also use the same statistics for measuring service, in that a canceled train does not count as delayed. Also it seems there are a lot of jobs with British Rail. All those gated stations and platforms with service personnel at those stations, gates and platforms to help people with valid tickets and non-opening gates. And many conductors on the trains, at least on the ones that run, calling out for tickets of newly boarded passengers only.
The British rail users remain kind and polite under all of this and show patience in queus. The train conductor on the Penmere branch line gracefully accepting my written-down reservation number, despite regulations, for I only could collect my on-line booked ticket at a Truro ticket machine.