And he ignores that over-complicated (in gwern's view) cost over a trillion dollars in US response, from NSA to TSA to Afghan and Iraq war.
Terrorists are by definition extremists. They want to upset the status quo to force people to take sides and create a situation where they feel they, who are righteous, have a better chance of being successful or at least relevant. Whether that is a race war, holy war or revolution. The killing itself isn't particularly relevant until your fighting over land and then normally in form of ethnic cleansing.
The analysis you linked misses a the point of e.g. the terrorist plot in Norway. It's wasn't just about killing people, he deliberately tried to effect politics by killing a generation of people he disagreed with. He also believed that it was part of and going to lead to a larger conflict.