Brenton Tarrant was far more intelligent than people give him credit for. The purpose of his attacks was to throw a metaphorical gas can into the furnace of racial relations, and I'd say he did a superb job.
The devide between Muslims and whites has never been so large in a very long time. He probably bought the race war forward by entire decades.
Fact of the matter is, he saw a problem and he created a solution, which is far more than any of us are ever gonna do.
Thanks to Brenton, the whites will rise again within our lifetime.