I'll have to disagree with your assertion of popular vote being an inherently better solution as I've seen this happen on a couple of occasions. The pitfall is you'll find that the larger scale models tend to win the votes regardless of the work actually put into the models that have been entered. I've seen a kitbashed HO caboose that had full underbody detailing, wire grab irons, and completely scratchbuilt fabricated wire end railings that had scored 100-points at an NMRA contest lose a popular vote contest to a stock Aristo-Craft G-scale caboose that only had a decal job applied. Who had the "better" model in that case?
My observation from 15 or so years of hanging around contests is that the sure way to win a popular vote is to include figures, such as a couple of guys on a flat car, wrestling with a load. Even a happy young couple on the observation platform will do it. Great scratch building?? Great prototype accuracy?? Naw. The voters are just going for stuff that is fun to look at — or anything humorous.