There was no single reason. It will take a detailed analysis and comparison to understand all the differences. In addition to other points made here, they happened at different times of day, and in Turkey there were aftershocks that were as bad as the initial Nisqually quake. And earthquakes are all different: some last longer, they cause different motion (up/down, sideways, rotation).

But you can see for yourself that they were just vastly different phenomena. The Nisqually quake caused visible cracks that were maybe a meter wide. You could hop across from one foot to another. The one in Turkey caused visible rifts the size of a large river, dozens of meters wide in places.

https://www.insider.com/turkey-earthquake-olive-grove-deep-chasm-split-2023-2