This is cherrypicking in the most bizarre way: if you can't explain the earlier oscillation, why should I accept the later oscillation? Which also doesn't line up with the type internet gaming which was exploited around the 2010s mark where alt-right groups began aggressively recruiting out of the gaming community via the "gamergate" movement.
In every case you're datapoints don't make any sense - there weren't 12 years olds playing Call Of Duty in 1985 and learning to scream racial and sexual epithets in voice chat. Games with a substantial violent component - the first person shooters - Wolfenstein 3D came out in 1992.
Which still doesn't actually explain anything, because it's not remotely clear how "shooting nazis" lines up with excluding women from CS.