Humans will always kill each other regardless of how we trying to take away the means to do so. Since 2010, there have been more than 1,900 reports of attacks involving corrosive fluids in London. They were used in 458 crimes last year, compared to 261 in 2015, according to Met Police figures. Lets also not forget that most terrorist attacks are being carried out with knives, vehicles, and explosives. I believe that if more people carried guns the three knife wielding terrorists in London would have been stopped much sooner with less loss of life.
As for me, I would rather be shot than have acid spayed in my face.