I've only watched a few times, but I heard that them flopping was because Andre 3000 looked bored? I only watched a few songs and it was okay.
like it isn't EDM's fault. High energy concerts are fun, and concerts in which the artists aren't really putting much effort into it are boring.
I also think people are unfair on EDM. Like, people are quick to dismiss dubstep and related genre as "stupid" or whatever, but those concerts are ridiculously fun, high or not.
Like Ryan said, I feel like Outkast is the sum of their newer hits to their audience. Like not that many people would come out for the stuff they put out in the '90s, other than a couple songs. They probably put on a rap concert when people were expecting a set of "Hey Ya!" and "I like the way you move". I'm sure people enjoyed it.