Worth bearing in mind that, in this day and age, the non-enthusiast market are your bread and butter. As some of you know in my voluntary life I look after marketing for DCDR and Táilte Tours, in both cases it's the non-enthusiasts that make up the critical mass to make events viable. What's interesting is the old notion that you have to have steam to win the general public isn't necessarily the case, both groups I work with have had to use 1980s/90s vintage diesel railcar stock and with the right proposition non-enthusiasts will and do travel.
It's been a decade or so since I was involved with RPSI but the same rang true there too (non-enthusiasts being the main costumer base, not the railcars!).