I used to be really into WWII shit. guns, tanks, planes, ships, all of it. I love the way they look, I loved (and sti love) going to air museums and living history events and stuff like that. but at the end of the day they are machines for killing. I mean obviously there's more to it than that but even something gorgeous like a P-51 mustang or something mechanically interesting like a Lüger are supposed to be for killing, or increasing the chances of someone else on your team to be able to kill more effectively.
Trains are different. they are interesting for a lot of the same reasons firearms are interesting - different countries with different economies and geography come up with different solutions. They define whole eras in history and landscapes. They are marvels of mechanical engineering and best of all, they connect people and make their lives better. it's wholesome.
also there's accessibility - a lot of us adore our local transportation systems and rely on them, but firearm ownership is not possible for a lot of reasons, like legal, financial, etc. so that's my perspective, I hope that answers your question.