The forward view was a universally popular thing among the passengers when introduced on the modernisation plan trains (actually it first came on GWR railcars). I don't believe that vehicle designers can't meet modern end loadings without eliminating it - the same sort of excuse as being unable to design the seats to line up with the windows any longer.
Am I correct that there was pressure from the drivers to eliminate it? The blinds were always left open, apart from maybe the one directly behind the driver at night to avoid reflections, until some time in the 1970s. There was an accident at that time with an official report, I believe it was on the Marylebone Line, where the driver's statement was contradicted by an enthusiast who had been travelling in the front seat right behind, and the inspecting officer showed he believed this alternative evidence, corroborated by other findings. Certainly after this time I never saw the blinds on this route ever open again, and it progressively seemed to spread.