The passengers (not customers) complain when we don't hold a train for you.
The passengers complain when the train is late at your destination.
Scenario 1: I catch the 17:45 from Paddington to Swindon, with a view to changing onto the 18:44 Southampton train at Swindon. But then the 17:45 gets held up by a few minutes ("goats on the line at Cholsey") and as I and others making the connection run from platform 4 to the bay at Swindon, the conductor sees us coming, shakes his watch, and closes the doors.
Scenario 2: I start to dash down the steps at the Hammersmith and Teacup platform at Paddington, but when I'm just a few steps down the doors are closed and the train departs.
Simple, I leave on time and wait for no runners, normally pointing at my watch to show I'm on time.
You may call it bad (customer) service. I call it good for the passengers who are sat down waiting for me to convey them to there destination.
I call your approach reasonable in Scenario 2. But I accept your invitation to call it bad customer service in scenario 1 ... and I suspect that view would be shared by anyone who was on the train, realised what had happened, and realised the effect of saving that few seconds on passengers for Dilton Marsh (2 hour and 22 minute delay, and an extra change), Melksham (don't even ask when the next train is), etc
We're posting in the "London to Reading" section where trains are more frequent, so perhaps more "Scenario 2" stuff. But I do think that people have every right to complain if they've been waiting on the concourse and not been given long enough to get to the platform. If you can't avoid justifiable complaints, someone should look at fixing the system.
P.S. Once you chaps start running a proper TransWilts service - the extra trains as defined by Network Rail's
GWRUS▸ - then I'll say a big thank you and say "We are scenario 2 too now". The EXTRA hourly service would mean that missing the 18:44 would simply drop us back to the 19:14 - not 22:01 at Dilton Marsh, but 20:10.