Railways should be about getting from A to B. They are an expensive and (if steam/diesel) a polluting way of providing mere titillation, which seems to be the raison-d'etre of many of the so-called heritage lines. Where possible they need to run to junction stations served by other public transport services so at the very least (if only at weekends/holiday times) they can contribute to public transport provision. For example, the SVR now provides the only public transport to Bridgnorth on Sundays.
Not all railways are about getting from A to B. As much as I think that heritage railways should do what they can to help the surrounding area, they are not there to transport people from A to B. I have been to the NYMR railway before, and I went from Pickering to Whitby (the whole line). However, this was not me going from A to B, as I went specifically to the NYMR for a heritage train ride. Whitby just so happened to be the end of the line.
I think that, if a heritage line can afford to do so, they
should run to a national rail station; but not to move people about - to increase visitors. A heritage line is going to be no use to the average commuter. 25mph? When a bus, which, admittedly, may stop at more places, can go twice that speed? There is no chance of a heritage line running a commuter service.
In terms of the SVR, I have been there many times and I have rarely seen people using it as a way to get to Bridgnorth; potentially because the railway is so high up above the section of the town near it.
-Peter