In message , Nicholas F
Hodder writes
For the same reason staff at Waterloo deny that virtually every train
that departs will stop at Clapham Common. To stop people getting on!!

So are you saying that station staff and train drivers involved are liars
and have a policy of deliberate misinformation?

There appears to be a policy of disinformation regarding Clapham
Junction, yes. Probably Watford Junction too (for northbound former
Intercity services). There is also deliberate misinformation at Kings
Cross regarding the destination of certain trains. They announce
"Foxton" when the train actually goes to Cambridge. In all cases they
appear to believe that the level of misinformation is justified in the
Great Scheme Of Things.
--
Roland Perry