But it isn’t a good point absent the bad assumption that the mentally ill are more dangerous. It only takes one bicyclist that’s fallen off his bike to kill you. So what?
Purple call the police on someone yelling. A mentally ill person yelling isn't a danger. They might be in crisis or pain, or they might be unable to effectively communicate.
A gun didn't help in any of those, the vast, vast majority of cases.
I don't think doing an action to have the policed called on you is the best approach, considering it can be weaponized by dishonest actors.