It's also worth pointing out that Manchester - Llandudno, Birmingham - Shrewsbury services are also "jam-packed" at peak times, with many people standing, and I can't help thinking there's a first class market on this route also.
Where there are packed 2 car trains, first class probably isn;t justifiable on moral grounds!
If I were starting from scratch, the routes that I think wuld merit some sort of premium or first class accommodation would be Manchester to Cardiff and Holyhead to Birmingham and Cardiff. I think there ar eprobably more routes across the UK that would warrant FC than currently exist.
That's just my personal view, though, there ar ea lot of people out there who think it should be completely abolished!