You would have a hard enough time trying to make law abiding people put this on their AR's, and how do you force this on the non law abiding citizens ?
1. We do not expect a perfect permanent solution, which never exists. Hopefully the total number of casualties would be greatly reduced. Some proactive actions could be taken timely.
2. We can do our currently best for now. Then carry out ongoing improvement later on, in respond to future development.
3. Doing nothing now would not be a good policy. Further delay would cause daily fear to most citizens, children and adults included.
4. Surely potentially hand guns in the future would be used instead, after re-designing AR-15 with GPS built-in. Again, the total casualties would be greatly reduced.