You have NO IDEA how effective the finger scanner will be.
Because it's an added layer on top of a system that already sometimes fail (guns jam or sometimes safeties will not release), and furthermore it's an electric system requiring power to function - I can guarantee it will increase the failure rate in successful access to gun for self defense.
To put that in real world terms, lets go for a very low figure and say the increase in failures means there are twenty more women raped in a year. Why would you be for that? Doesn't sound like a good tradeoff to me.
In reality of course the increase in allowed raped would be much higher because it would be mostly females purchasing a "smart" gun, misled by people like yourself into thinking they are better in some way... it's kind of like you are just one step removed from raping them.