First, watch your language.
Well, probably I should re-phrase my 2nd paragraph if it will make you feel better, adding "exclude US" there. Happy? If not, maybe buy yourself a ticket to Christchurch and ask the shooter why he didn't use a suppressor for killing more after 2 years planning.
I am not asking for restrictions for reasonable and legal use of suppressor and/or firearms. I personally own firearms for sports purpose.
And for this incident, NZ is complete a different story comparing to US, most of police officers do not carry firearms there even there are lots of gun owners. See the difference?
I know in US suppressor has been regulated at least good enough from my understanding, but in NZ it's pretty much like you can buy from ebay without license. Most of people stay safe because they do not use their firearms for illegal stuff or killing, but if someone like this shooter abused this kind of "trust" for massacre with easy access to certain gears, that would be a nightmare. You see where I am coming from? At least, NZ will do something to prevent similar incident happens again. Last one was around 1990 and the one before seems back to 1943.