I can see both sides of the argument.
But I will agree that some First Class Fares are unrealistically priced. For example a day return:
First Off Peak Return - Bath Spa - Bristol Temple Meads: ^15.75* (Approx - 13 Minutes - Approx 12 Miles)
First Off Peak Return - Penzance - Plymouth: ^34.00* (Approx - 2 Hours - Approx 80 Miles)
*No FCR between Bath Spa and Bristol Temple Meads. FCR Between Plymouth and Penzance is ^24.50
Perhaps a small reduction in some First Class fares might convince some Standard Class Passengers to upgrade to First Class thus freeing up some of these 'empty' carriages. But I agree with the other comments on First Class in the Peaks from and into Paddington. Can often be more than a bit cosy...!