One would be that this is an added point of failure on a tool which REALLY needs to be consistent when you need it. Conventional "safety"* mechanisms are alread

One would be that this is an added point of failure on a tool which REALLY needs to be consistent when you need it. Conventional "safety"* mechanisms are already often avoided for certain use cases because they add another element of complexity which needs to be factored in. *safety is in quotes because certain mechanisms don't necessarily improve safety assuming proper handling. A holstered gun without a safety catch or grip safety isn't really any more dangerous. If you operate under the idea that you are only going to draw a gun if you need it to defend yourself from a deadly threat then the "safety" is redundant and makes it more likely you will make a mistake.