“Tell me, would you buy a fire extinguisher that requires you to unlock it with your fingerprint before you use it?”
My fire extinguishers have a disposable pin that you have to pull to prevent accidental discharge.
This type of trigger-safety a good match for a fire extinguisher, because the consequences of accidentally discharging a fire extinguisher is generally non-fatal: a trip to the hardware store, and a few dollars out of pocket. On the other hand, the consequences of a random person using the fire extinguisher is likely to save tens of thousands of dollars.
Applying the same logic to the trigger-safety of a firearm comes out with a very different answer. Accidental discharges of firearms can be as lethal as a fire, and far more rapidly — so the risk-balance here is very different than it is for a fire extinguisher. Also, while a firearm can be relatively safe in the hands of a person with a working conscience and a working understanding of gun safety, they’re incredibly dangerous in clueless or malicious hands. I mean, seriously would you hand a loaded gun to every person who visits your home? Would you hand loaded a fire extinguisher to every person who visits your home? The answer is obvious — nobody hands a loaded gun to somebody until they’ve assed their ability to handle it safely.
Authenticating the user of the gun before allowing it to fire seems like a way to have your cake and eat it to in terms of the safety and utility of the device.