Incidentally, I don't find the idea of ripping off tourists and
non-Londoners (which has been mentioned as a target) remotely
acceptable.

Tourists from abroad get offered all sorts of attractive travelcard
options that we never hear about.

Does this still happen? The Visitor Travelcard has gone now but it seemed a
very flexible and cheap deal. However tourists arriving at Heathrow without
one, or needing to top and tail it with other tickets, still seemed to be
able to get tickets for any period they liked at prices that bore no
relation to anything available to the rest of us.