Tarrant addresses this directly in his manifesto. If your race and culture is snuffed out as the end result of mass migration does it matter if the immigrants were violent or not? Is he right about the birthrates and stuff? And he certainly employed memes, but his audience is everyone. This guy is not dumb, meming and alluding to pewdiepie and all that are incredibly smart ways to play the media like a fiddle and disseminate his message. It wasn't just to make an epic thread on 8chan and get a lot of (you)s.