Passenger operations...
Regarding the question about not modeling the passenger car operations...
I guess that there were a number of factors. First, when I designed my layout back in 1980, I wasn't that knowledgeable about any of the operations of the prototype. That might seem strange these days but remember that true prototype modeling was in its infancy in those days. This was before the Internet and research resources were more "hands on" than today. If you wanted to gain knowledge about your prototype, you talked to the rail fans who had ridden it and photographed it. When I started modeling the YV, there was only one book on the YV and that book, like most published in the 1960s-1970s, didn't discuss operations per se. (My own book on the YV, Trains to Yosemite, was published in 2005 and includes an entire chapter on operations.)
While I knew that the YV ran passenger trains when I designed my layout, I wasn't that interested in passenger trains...the railroad also ran log trains and regular freight trains which provided much more switching opportunities that were the main operational interest back in the 1980s. Compared to operators picking up and setting out freight cars, the passenger trains only stopped at two stations along the way to take water. So, running passenger trains was much like running a commuter train!
Also, in those days when I designed my layout, the operational and layout design emphasis was on including sufficient staging...design a layout based on a railroad which connected to other prototypes on both ends and run multiple trains moving cars from staging on one end to the staging on other end and visa versa. My prototype interchanged with the SP and ATSF on one end and dead-ended at Yosemite National Park on the other end...not the "recommended standard" in those days. Compared to through freight trains, the articles on layout design in those days rarely mentioned passenger train operations.
Another factor...the layout design "bible" in those days was John Armstrong's soft-cover book on layout design. As I recall, John provided design guidelines based on the largest locomotive which might be run over a layout. In my case, that was a 2-6-0 which, as I recall, resulted in a 22" minimum radius curve.That is considered a pretty sharp curve these days but I incorporated spiral easements into each curve which helped enormously in "camouflaging" those relatively sharp curves. (On the other hand, with 2-6-0s and 4-4-0s and 40-foot freight cars, those curves don't appear that sharp.) The minimum radius curves suggested by John Armstrong didn't (as I recall) include passenger cars. Even if they did, I would have ignored them. More importantly, a larger minimum radius curve would have resulted in larger turnback curves and tighter aisles, something that would have resulted in even more compromises.
As an aside, when I was building scenery, my only concern was to ensure that rock faces and other things like trees and structures adjacent to the track clear a NMRA gage. I only discovered later that 80-foot Pullmans couldn't clear those rock faces.
The other factor (some of which is only in hindsight) is the total length of my mainline. My double-deck layout is built in a 20'x20' space. My article in the January 2000 issue of Model Railroader discusses my choices for my layout design. In that article, I discuss how many choices influence design factors including train length, maximum grades, and passing track lengths. My maximum hidden grade is 2.3% (my visible grades are equal or less than the prototype). That limits my freight trains to 4-5 cars upgrade depending on the type of cars (empty hopper cars, empty log cars, or general freight cars) and the locomotive's tractive effort. That freight car limitation sets the minimum length of passing sidings on the layout. The length of passing sidings influences the distance between "towns" or switching locations since I prefer to not have a locomotive in one "town" while the caboose has been dropped on the mainline in another town. As I mentioned in this MRH article, a typical summer passenger train would have included a 40-foot-long RPO car, a leased SP diner, one or two heavyweight Pullmans (sometimes more), and the YV’s 69-foot-long wood observation car. A train of that length would have made the layout appear much smaller since the locomotive would, in many places, been in one town while the observation car hadn't yet cleared the station in the previous town.
So, in summary...my decision was based on lack of any interest in passenger train operations, very little prototype interaction between the passenger trains and freight trains, more interest in freight train operations back when I designed my layout, and the need to increase the minimum radius used on the layout (as well as the length of passing sidings and the distance between towns) to accommodate passenger trains. Even in hindsight, I think that these were all worthwhile considerations. Besides, if you come to view my layout, you would never know that I didn't model the passenger trains...there are a couple of full-size Pullmans positioned in the shade under the train shed at El Portal, waiting for the evening trip back to Merced. For operators who start their working day at around 8:00 am, those passenger trains were already close to arriving at El Portal.