Well, if the rails are not going in your direction, perhaps you're on the wrong train.Where is the immersion for players like myself, that cannot or are not interested in doing route building.
As for the lack of perceived quality, we all know that N3V makes very few of the object themselves. Trainz is a creators dream workshop where enthusiasts make objects and share with others, either for free or as payware.
And while TSC might have a shed load of stuff, from what I've heard, it apparently doesn't go very far and only where they decide you may go. Perusing the TSC themed forums, one constant complaint is that the routes they provide are too short.