I can see the attraction of model railroads, lots of available plans but is it really necessary to imitate the real life physical constraints too? I've met many modelers who wished they had more space than a small corner of a room. Even those that had the use of an entire room wished there was more. The standard joke was that if only they had a barn, then they could really build their ideal layout. Well with Trainz, everyone has a barn, or even bigger - a hanger - to build their dream layout. No need to squeeze unprototypical radius curves into available space.
Or am I reading it wrong, are those constraints the attraction?