@ underfire
Not a "structure" fire - it was a "large passenger vehicle" fire.
First priority is evacuation and rescue - and blasting the only exits with high-pressure foam and water will not enhance that objective. From about 5:50 on one can see firefighters entering the cabin via the doors for search and rescue (did pull 5 people out), and you don't want to trap them by blasting the doors either.
Second "first" priority is fire suppression to allow more time for search and rescue - thus the heavy equipment is focused on the active fire in the vicinity of the right wing, fuel tanks and spilled fuel. With some occasional overspray onto the cabin roof.
The larger apparatus cannot be very effective in hosing down the whole interior through a smallish doorway anyway. What you see starting about 10:00 is first the rescue crews evacuating via the slides, and then handlines being manhandled up the slides to the doors - and a handline nozzle right at the doorway can swivel around and cover the whole interior much more effectively.
But they don't put a lot of effort (or risk personnel) into saving the aircraft - it was already "junk" by the time it stopped moving. The only other reason to fight a structure fire down to the last spark - to protect surrounding structures - also doesn't apply in this case.
It's just a whole different scenario.
But - the SFO emergency services certainly came in for some criticism of training, communications, protocols for avoiding injured passengers on the ground, and (in direct connection to your question) failing to adequately use two HRETs (high-reach extendable turrets) with skin-piercing nozzles for firefighting within the cabin.
https://www.ntsb.gov/news/events/Pag...-Abstract.aspx