The remote connection to safety (did you mean security?) would be that static source analysis tools don't work as reliably with dynamic languages. That matters at Google. But you don't even have to think as hard about it: Python is simply comparatively slow and inefficient. Google's fleet is large. It pays off to use more efficient languages.
(There's also the whole thing about Python being largely single threaded and computers being very wide these days, as well as being a terrible memory hog and memory making up half the cost of servers.)
The remote connection to safety (did you mean security?) would be that static source analysis tools don't work as reliably with dynamic languages. That matters at Google. But you don't even have to think as hard about it: Python is simply comparatively slow and inefficient. Google's fleet is large. It pays off to use more efficient languages.
(There's also the whole thing about Python being largely single threaded and computers being very wide these days, as well as being a terrible memory hog and memory making up half the cost of servers.)