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?
Around 20 years or so ago I attended a one-day meet in Sonora, CA. My friend brought his recently finished, nearly 100% scratch built, Westside Lumber Company narrow gauge Heisler. My friend's build quality was world class and one of his scratch built shays took 1st place steam at a National NMRA convention. This Heisler's work was an equal to his earlier shay. Popular vote Had the guy who brought two PFM geared locos take 1st and 2nd. !st place brass engine had moose antlers made from brass shim stock attached to the headlight, otherwise an as-built PFM shay. My friend wasn't as bothered about the slight it as me, but the lesson for me if someone wants to enter a judged contest, avoid a popular vote. The public's poor ability to judge built models makes any award from such contests meaningless.
It is well known along the NMRA contest circuit that the savvy builders who are out for bagging awards know ways in which prototypes are selected and other tricks, such as scale size, to rack up the points for a win.