There’s been some conradictory evidence on whether better screening processes for gun buyers would result in less people seeking care. In Connecticut, under their relatively new law to seize firearms from those who are threat to self or others, it’s worked the opposite way. It’s getting more people in treatment, not less.
Remember, too, that cultural mores about guns are changing in this very moment, post-Parkland.
I also generally don’t buy the argument that you should resist doing something good (better background checks) because of imperfections in the justice system (institutionalized racial bias). I’ve seen this argument made to allow convicted felons legally buy guns on occasions. I think we should work toward both better checks and a fairer justice system as a gun control movement. I have long thought that common ground could be found with advocates of decriminilazation, for example, by working on reforming sentences for the actual shooters in low-level gun crimes (as opposed to those profiting at the top of the chain from illicit gun trafficking). I think it’s a wonderful thing in general that gun control advocates are now thinking more about criminal justice issues. It’s important.
To me, the state’s interest in using its police powers takes higher priority over privacy concerns given the level our gun violence has reached in this society. And privacy concerns haven’t proven to be an issue under 20 years of NICS, as far as I’m aware.