Yes. And these duties can easily conflict (in which case preservation of life always has priority). Another reason to let a house burn is because there are still firefighters in there, searching for people. The clothing of firefighters (at least the Nomex based used here) is extremely good at insulating from heat, but looses almost all protection the moment it gets wet, as the water starts boiling. Obviously that is extremely dangerous for the wearer.

This means that often saving lives and saving property can not be done simultaneously. Some time ago here there was a report about house ownwers getting upset at firefighters for just standing around "doing nothing", while their property burned, which happened exactly for the reason outlined above.