Is it okay for a firefighter to shoot anyone he sees with a fire extinguisher? No.
Is it okay for a teacher to shoot anyone she sees reading a book outside of class? Don't be ridiculous!
Is it okay for an accountant to shoot anyone he sees doing math or using the calculator on his phone? Obviously not.
Not unless the individual was in the process of using those items to violate life, liberty, or property.
Then why would anyone believe it's okay for a cop to shoot anyone he sees simply carrying a weapon? It's not, and only a delusional copsucker would argue that it is. "Officer safety" is a poor excuse for cowardly murder.