While I am in awe of the great modelers I see, I have no aspirations of modeling. I may try now and then, as I like a challenge, but for me, the interest in trains is the emotional interest in trains from places I have been or like to go. So shiny plastic buildings and vehicles, unweathered trains, simple landscapes, etc. work for me since I am not looking at the details, but rather the whole tie back to where I've been or want to go.
As we travel to Japan every other year, more or less, to visit the wife's family and to see her country and experience it, and as we travel by train a whole ton while there, I like the Japanese themed trains. It invokes the emotional feel of being there and planning the next trip there. I overlook the lack of details (weathering, etc) and just like playing with the trains. I run non-prototypical batches (ie, JR West and JR East on the same layout at the same time). As long as it evokes the image of Japan for me, I am game.
The same thing applies to the European trains (mostly Germany/Austria/Switzerland). Not only did I live in Germany twice (86-87, 91-93), and ride a lot of trains during the first sojourn, I've been back a few times and ridden some trains. But more than that, to me, the German trains means a trip -- a vacation -- even if only in distant dreams. (I will finally go back in 2020 and ride a bunch of trains when I go to a missionary reunion in Munich). I don't go to Europe as often as Japan, but it still holds the emotional attachment of having lived there and ridden trains there, and of a potential future trip there to look forward to. To dream about. So that is why I like the European trains -- especially the German/Austrian/Swiss.
I don't have or play with US model trains, though I love to look at all you guys' layouts and trains and great modeling skills. I have no real connection to the US trains. I rarely see them (mostly occasionally see the Frontrunner commuter train and I do see the light rail regularly) -- only see them when I drive up to Wyoming or very occasionally when they run through the valley. And we don't ride trains much in the US and I have not ridden more than light rail types since I rode a commuter train to Boston back in the late 80s. So there is a geek interest in looking at them and their technology and stuff, but no real emotional need to have them myself.
So, to sum up a long post, I agree with
@Bruette -- I'll never be a great model railroader (though once I get my train room built and eventually get into retirement, I'll make a good go at it), I just like to run them and set up stuff to help me get excited about the next trip, to pretend to be there, and to remember the past trips.