Open-source intelligence analysts reported that Crooks didn’t appear to use mainstream social media channels such as Facebook or Instagram and had an almost negligible internet footprint, which is highly unusual for a 20-year-old. Instead, analysts said that Crooks corresponded with friends and associates on a Discord server that they were now trying to access.
Discord servers are restricted ring-fenced sections of the internet. They are often used by gaming groups and communities as secure chat rooms but are also used by fringe organisations to push their ideologies and discuss wild conspiracy theories and plots.
This is my take as well. If this were at all politically motivated, we would be reading his manifesto right now. Or at least his unhinged posts on 4chan/facebook. The fact that there are none of those things leads me to believe that this is just a guy who wanted to be epic. The target was irrelevant, if it was Genocide Joe on that stage he would have still taken the shot.