Reading is not an ideal place to terminate due to the lack of direct connections from there. GWR services are available for those heading west which are already covered by XC. Oxford and Banbury only have Chiltern connections
Nobody uses CrossCountry for travelling to London so this can be ignored. People predominantly use XC for north to south journeys.
Reading is a destination in itself, being a regional centre of employment, university town and so on. I also think that you undersell just how many connections there are from Reading. Not everyone is going to change for London, Oxford/Banbury or Swindon/Bristol and points west. Reading is a hub for a very large number of feeder services that bring in and take out large numbers of passengers to connect with long distance services there in preference to going into London.
On your second point, I'm not so sure that
"nobody uses CrossCountry for travelling to London", especially from Oxford. A quick glance at the NR journey planner shows that it takes only 4 minutes longer from Oxford to Paddington via XC with a change than going direct, effectively giving Oxford an extra fast London service each hour. There's an awful lot that get on at Oxford at all times of day, and I can't believe that none of them are ultimately going on to London. Obviously I do understand that folk prefer fast, direct journeys over slow circuitous ones, but the XC option allows passengers to skip the Slough stop that the direct services make, which is something that some passengers may prefer to do.
Now of course, any putative Basingstoke service would still serve Reading and still serve that need, but I do think you're being a bit hasty in writing it off as a destination.
To address my point about the railway doing what is most convenient for them and them only: We have seen time and time again examples of good journey opportunities gone over night. Once the service is removed it rarely ever returns. It is a case of won’t rather than can’t.
I disagree. Compared to the original iteration of the covid response, this is an
additional service that had not previously existed. That it's primary purpose is to maintain staff competencies is really neither here nor there. Also, given the talk about restoring the pre-covid service from May, I'm unsure why you are worried about the former service not returning. That this
specific service is primarily for operational purposes is, as I've explained, a way of ensuring that the pre-covid service can be reintroduced seamlessly, thereby ensuring that the service does not disappear due to staff competencies having been lost.
But on the wider point, any service has to be capable of being resourced. Extending the service from Reading to Basingstoke would require additional units and crew. It would take it out of range of Manchester depot, make it difficult to diagram for Birmingham depot and would shift a lot of additional work onto Bournemouth depot. These aren't excuses, but they are challenges that would need to be considered and addressed. Any extension to the service has to be looked at carefully and decisions made about how it can be delivered. It may seem like commonsense to you to extend a service to give what you consider to be better connectivity and merely "operational convenience" when they are not, but you cannot simply start joining dots and then complain when the railway operators disagree for, I suspect, very good, sound reasons.
Besides, XC are still serving the South Coast and giving connectivity with the SWR network with the Bournemouth and Southampton services.