The biggest drawback I see to
The biggest drawback I see to this from the standpoint of the consumer is one is buying a pig in a poke. Buying an untried unseen product never has appealed to me. Think back to the pre-spectrum days of Bachmann locomotives for example. They had some stinkers in that product line and retail prices were fairly high. The ones I am referring to might not run for more than a few hours and were so bad that another company made a kit that would replace the entire drive mechanism, allowing the modeler to reuse the shell.
I have also purchased other items from manufacturers and been displeased with their operation characteristics, granted I expect a lot from my rolling stock in the way it performs. I have since decided to buy only kits so I get to build them.
I fully expect to take every locomotive I buy apart to clean and lubricate it as well as make adjustments to all contacts, and possibly add weight, and or a sound decoder and speaker. I have seen some that are very poor performers where it comes to pulling power by comparison to other models, and as such might not be good choices to improve on.
I have never bought a house, auto, motorcycle, or piece of furniture with out testing it or seeing the actual item prior to purchase. I see no reason to do this with my hobby. If it means I miss out on items so be it, it also means the maker is missing out on sales. If they are concerned about being able to sell enough of the product they might wish to do a better job of marketing research.
In reference to the generic models there is quite a market for them. This would also be true for many time periods. The USRA era of standard steam locomotive design for example. Individual railroads added details as it suited them. An easy way to have model specific versions is to make the different details in a package for the different versions and have the modeler install them. Also great for the free-lancer as well. Decals could be included and the modeler could apply them as well. The diesel era produces similar chances for standardization but might involve painted and decorated models with separately added details. Some of the paint schemes were fairly complex and might be more appealing if done by the manufacturer.
Think of the economy for the hobby shop owner or online retailer. Buy one model, with included detail pack and decals for all the roads. I have seen 8 or more road names on one decal sheet with data. Easy to keep items in stock no more guessing on how many of each version to buy.
The basic model with add on details could also do well with the example caboose. Think of the wide vision, or North Eastern styles for example with different details. Modeler buys one and paints it and the added details and decals it to fit his era and road. Many freight cars were manufactured and sold to several different railroads, only differing in details. Send me back to the days of the full shelves and detail parts that can allow me to build great models that run well.
There will still be the market for the limited run models just as there was the market for brass but not all of us desire the high priced limited appeal models that come from those efforts.