I like this video. I've never gone to VidCon but nowadays I don't think I'd want to. Like, as you describe it, it does sound horrible. I'm sure a year or two ago it was great but as YouTubers become more famous and exalted and more and more people go it seems the ridiculous numbers will ruin the experience, if they haven't already.
As you say, stop the signings is a good idea IMO, but maybe it would overintellectualise VidCon if all that's going on is panels, and it would become less of a meet your fans in person thing. After all, VidCon was only partly started to be "interesting", but the main reason was to bring an online community into the real world for a week each year.
Maybe they should start doing a number of VidCons, each one with their own set of creators. It would thin out the numbers, and it could be set up so massive creators like Philly D, Epic Meal Time and PewDiePie don't flood the place with all of their fans all at once. Of course the issues are that people have to pay for these things themselves, so a creator may have to choose which to go to based on cost, and perhaps fans would have to choose which VidCon to go to, choosing between their favourite creators.
So yeah, I don't know really. Perhaps the answer is as simple as choosing a bigger venue or using multiple venues in the area. That would bring in extra cost, but maybe Google could help financially if they don't already?
Still, very interesting video, and good ideas.