Whoever does not say, I think that having a gun in your pocket will make you feel calmer. Of course, these weapons will not save from the terrorist, but the house will always be protected by what.
Terrorists are terrorists because they are too scared to be soldiers. They will be much more scared if they know people have guns to protect themselves. They might be scared enough to not even be terrorists.
Another choice would be a good permitted weapon, not just pistols and shotguns. If the assault rifles were in accessibility or grenades, then the terrorists did not prove their opinion with the shahid's belt, but with a poster in their hands.
What's a grenade? They are banned in all countries. Any weapon that leaves its traces and it is possible to track down the owner if the weapon is legal. Grenades do not leave such traces, and dangerous to others. As for guns in my country, no problem with them. I can have a legal gun, but mass shootings have not been recorded.