Explained in post 41. No need to repeat the points. If you can't see the difference between 100+ years of established workings on flaghips routes, and a brand new set up on a route that management will not have in primary focus, I don't really know what else I can say to help you.
Read Fiennes' book - I've quoted bits of it in earlier posts. The problem was that the line ran through a traffic desert west of Salisbury and there was very little, if any, commuting traffic to London from such distances in those days. Basingstoke was about as far from London as it went, similarly Reading was the effective limit from Paddington.
If we are talking about 1963 (which is, IIRC, when Wilton - Exeter went to the WR), this is simply not true for the WR. (I can't speak for the stations west of Basingstoke, but I don't believe it is true for those either.)
For example, in 1963 there were at least two through peak hour LHC trains per day serving Didcot - Thames Valley stations - Reading - Paddington. I think they came from Oxford, but can't swear to that. These were already Hymeks by the time I saw them, but I assume they were Hall or County-hauled before diesels became available. Didcot certainly had a couple (2? 3?) Counties allocated specifically for commuter trains into London.
There were commuters from the VAle of White Horse too before they closed stations like Wantage Rd and assumed everyone would henceforth drive to their enforced railhead at Didcot.
These were not unusual distances. On the GN there were similarly two loco-hauled peak hour through trains to KX (usually with New England A2s or A3s) that attracted commuters from Huntingdon, St Neots, Sandy and Biggleswade - we are talking 50 - 70 miles here - far greater distances than the 36 miles from PAD to Reading. On the LNW there were commuters from Northampton for sure, again, 65 miles from Euston.
Of course, commuting in terms of passenger numbers and distance was nothing like what we have today, but to say the commuter limit was Reading is simply false.
The GWR's steam shed at Southall supplied the 61XXs which covered the suburban services which essentially did not go much past Slough.
There was no commuting to London from those distances in those days. This is all post-fact rationalisation.
Of course, commuter workings got more intense the closer you got to London. Nobody would argue with that. But simply repeating your point and deeming any other argument is "post-fact rationalisation" doesn't make it so. It is not true that the limit for daily commuting on the WR c 1963 was Reading. Not in 1963, and not for some years before that, because I don't believe those trains suddenly appeared for the first time in the 1963 timetable.
There were not many through trains each day to Exeter and beyond from Waterloo either. Not all trains were like the ACE, nor were all days like summer Saturdays in the 1950s.
That is true (relatively) for almost every line emanating from London. It doesn't mean to say that there was not traffic to be had, even on winter Tuesdays, despite the original hope to close the LSW at Sherborne (another enforced railhead for folks from Yeovil). And, going back to the original point of the thread, I still say that had the line stayed in SR ownership, that that traffic could have been built up earlier and more easily than what ultimately transpired.
). So presumably it went 85 up to 90, then 100 when the Wessies came in. 
