Robin9 wrote:

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.

Having all-stops, slow suburban services would eat up another fast path on
a 2-track railway.

Being cynical, I suspect Chiltern deliberately makes those services
unpopular and so little-used. It would rather not run them at all, leaving
more paths for fast, longer distance, higher revenue services. The last
thing it wants is to have to increase the frequencies of its suburban
services because more people were using them. That would decrease its
overall revenues: each of those unprofitable slow stoppers probably
consumes two fast paths, that would generate far more revenue.