Is there any logic or consistent pattern to the way Chiltern
Railways serves the London suburban stations on the route
to High Wycombe? Marylebone Station feeds a minimal
suburban network and a straightforward, all-station-stopping
train once an hour would get the job done. Chiltern seems not
to agree.

Their method is to run trains to destinations way outside London
and very occasionally to stop a train at one suburban station.
That might be acceptable to someone travelling to and from
Central London but is quite useless for someone wishing to go
from, say, South Ruislip to Wembley.

Chiltern Railways is a commercially savvy TOC so I assume there
is some logic to their system.