Going off some simple figures the article provides, I'd estimate they make around $6 million per year. How is that not feasible? The way to do it is make slow upgrades like the Cog Railway in NH did. You can't just go out and buy all new engines and cars.
There is a way to make it viable, but to keep it running, like any buiseness, will require money. Sounds like this guy is a penny pencher who isn't ready to make a large investment on something that has already proven itself as a good buiseness.