I’m sure they will investigate why it burned so much. To be honest I’m not sure in the case of arson it’s possible to put in 100% sufficient systems that can always prevent such a catastrophic fire. It says in another article that an active sprinkler system was in place. I’d be surprised if it wasn’t to code, especially in California, for such a large facility. We should probably wait until this is investigated before we throw around such accusations.
If a sprinkler system can't put out a fire started by one guy with a lighter and some boxes (no chemical soaked rags, no gasoline, etc.), that building cannot be occupied.
Bank on it that the sprinkler system was to code for light industrial use but not for storing that volume of combustibles. Also bank on it that there were no internal walls with closing doors to stop the spread as you would do with combustibles.
I spent a lot of time going through sprinkler system installations for aircraft hangars and multi-use facilities. We even had hangars with two separate systems installed - one for aircraft and another for deployable assets. Someone has to spec the contents, determine the burn rate, determine the water pressure, and of course cut the check.
No one wants to cut the check.