I would agree. His assessment is historically laughable. Also, note that he doesn’t go into why the Serbs were supportive of a terrorist attack on the Austro-Hungarians.
Perhaps it’s an argument to support blaming GZ for any future race war.
When Push comes to Shove, all wars are about greed. The greed takes different forms, of course, but it is greed nonetheless. Excuses as to “why” are just that: Excuses. Muslims are greedy, and zealously so. But then, so are most politicians. Power, money, marbles, houses, land, all of it is about greed.