If you read my original posting, you will note that I took care to state "not obviously on the same station site that was closed"
I’m not sure where else would be any better. The railway turns north immediately on the London side of the original site, so realistically any alternative site isn’t going to be much closer - and to some extent may be worse as at least the old site allows people to have a scenic walk along the beach. At best the only obvious change I can see is putting a new station on the opposite side of the road bridge, but that doesn’t really change much in the grand scheme of things.
On a much larger scale of size, from what I have been told, the Exmouth to Paignton service seems to be an aid to the tourism of the area concerned, travelling both banks of the River Exe.
The thing with Exmouth to Paignton is that service seems to be able to hold its own even without any tourism traffic. It caters for a lot of local journeys, and links numerous well-populated areas for work, education and leisure.
There isn’t actually that much in Penzance, and St Ives will always be very seasonal.
I guess the other problem is that to run St Ives to Penzance with two trains is very tight, as it means covering St Erth to Penzance and back in under half an hour, which a Marazion stop is only going to make even harder to reliably achieve. The moment it can’t be done with two trains then the whole thing would become unviable I suspect, as during the summer to deliver a half-hourly St Ives service using a 4-car train, a Penzance extension makes the stock requirement goes from 2x 150 to 6x 150. Worse still if a longer train is required.
I think this all fits in the “would be nice” category, but unfortunately there seem to be practical reasons why it’s unlikely to happen.
