I think the downturn in the displays we're used to seeing could be due in part to those residents getting older and losing the ability to do outlandish displays. At least, that's what I've noticed in my community.
This article indicates that a new generation is starting to come along that will pick up where the previous generation left off. I guess the advent of LEDs and computer-controlled lights have captured the interest of younger adults that couldn't get themselves worked up over painted wood cut-outs and mechanical animation.
This is good news.