There's no doubt the steam locomotives are handsome and full of nostalgia, and no one ever accused the average diesel locomotive of being "handsome." However, trains, whether diesel or steam, still fascinate people. I'm not sure why, but I'm among them. I can watch trains go by all day. I always count the number of diesels pulling the train, mostly because it gives me a good idea of how long the train will be.
I also never thought about a diesel locomotive not having a transmission, but I'm not mechanically inclined. Still, it's interesting learning about how they work.