They fed off of his gun love. The guy sure loved his guns. Humans, apparently not.
The NRA feeds off of the symptom [disconnection/lack of community] to fill the fear that creates with a Substance — a Substance which gun owners like that shooter use repeatedly, buying more and more guns, more and more ammo.
Does this make the shooter feel more connected? More human? No. My guess is: less so, since now he’s being lumped in with the other nuts who own so many guns and he thinks he’s boxed in by people who want to control how many guns a person can get and what kind of checks need to take place.
It’s a lot like Facebook, cynically preying on our lack of community to provide us an addicting Substance which erodes community and self.