They're not deep thinkers...

They do, just never at rates that are come close to the straights, because it is a whole thing one has to set out organise (usual caveats about exceptions, notwithstanding).

I guess incels believe that they have a lower chance of procreating than the gays.

Until they relinquish their noxious views, they're probably right in that belief, but I'd imagine this guy & his associates are referring not to procreation, but to shifts in the social hierarchy.

It's the same pretty much everywhere and anytime conservatives try to use violence. They think people will flock to their cause but don't get that the vast majority of people, regardless of ideology, do not want to kill people and find murder reprehensible. This leads to these terrorists losing ground constantly and driving people who'd at least been uninterested in their worldview into being vehemently against it. Terrorism like this results in outcomes to the contrary of what the terrorists were trying to achieve.