I do not get why some people bash train watching modern trains and call it boring. I usually go to Folkston and Jacksonville at least once a year just to train watch. I still see a lot of mixed freight trains and see a wide variety of locomotives. Also back to the main topic, MTH makes starter sets with modern SD70ACe's for the people that like modern equipment. A lot of younger people in the hobby though are still interested in steam locomotives because of how animated they are compared to modern diesel locomotives and maybe some nostalgia for that era of railroading compared to the modern era.
I grew up around steam engines, and steam is in my blood. But my O-gauge trains are mostly diesels.
The reason for this is quite simple, I don't have enough space in my train room for the larger radius curves that most steam engines need. If I had more space, then I'd have more steam.
However, I'm quite happy with my collection of F units and RF-16's to pull my passenger trains. Whether it be steam or diesel hauled, nothing beats the beauty of a streamlined passenger train sweeping along the rails. 
