I can see why they removed passenger trains (complete duplication of existing facilities).
But they should have concentrated freight on the route and take freight off the other busy lines (i.e. WCML▸ ).
Then it could have been upgraded easily to HS▸ standard in the later part of the century when HS rail was becoming common - baring in mind that BR▸ still ran more 100 mph /100+ mph trains in 1990! It was the 90s when the Europe built lots more 200 mph lines (and we should have built the CTRL▸ and the GC» route then!).
Beeching was not far sighted in that way, it recognised the need to modernise and streamline BR but the commissioners of the report, the DoTp, saw motorways and road transport as the modern way and railways as worn out, expensive and old hat.
Copies of the Beeching report can be seen here -
http://www.railwaysarchive.co.uk/docSummary.php?docID=13http://www.railwaysarchive.co.uk/docSummary.php?docID=35Once the
LM▸ Region of BR had used the GC as it blockade buster for the electrification of the WCML in the 60's it needed to show a return on the investment to the
BRB‡ and DoTp closing the GC ensured traffic had to use the WCML, ironic today that the former "London Extension" of the GC is once again used for that purpose and even more so as the Chiltern Line (formerly "London Extension" of the GC) is seen as a prime route out of London for development to the Midlands and the North.
BR and the DoTp still used the Beeching formula well into the late 1970's as justification for closing lines and stations, including the Bourne End to High Wycombe line which was not in the original Beeching report as down for closure or station closures.