This is a good point. I don't wish to dismiss that today's corps are simply trying to detract from the past, but the works they put out have certainly become more cerebral. And it's because the objective over the years has changed from "please the audience" to "please the judge." It's like taking DCI from a boot-stomping barn dance to a quaint and stuffy wine-tasting (probably not the best analogy but that's the first comparison to come to mind.) The average joe getting introduced to DCI isn't really going to get it off the bat unless (like the original poster mentioned) they get out the old tapes and play something that appeals to the gut emotion.
The one segment that got me here was (paraphrasing) "the corps fed off the crowd, the crowd fed off the corps, and the corps fed more off the crowd...."
One heck of a performance can be inspired when the fan element is mixed in. You can have the most kalidoscopic, whiplash visuals matched with the most complex musical execution -- but you'll only get golf claps without the crowd element.
That's why Phantom '08 has been referenced so much. They told a story with the right mix to stir the crowd to chant the "I Am Spartacus" battle cry just from the pure emotion the corps generated. The corps and crowd fed off each other to make it one of the more memorable performances of recent time. The rest is history.
I haven't been involved as much with the activity for the past 5 years, but check back around every August to see the state of affairs around the community. To use my analogy, I bring my boots just in case to see if a barn dance is about to break out. To my dismay, it's just another wine tasting.