Wrap your head around actual statistics. Each throw a QB makes is an independent event, with numerous variables affecting the outcome. If you throw into coverage, or across the field, or fail to read coverages, each of these independent variables affects the success of a single throw. A You cut down picks by controlling and minimizing the effect of the independent variables.
Or, in your analogy, you cut down your STD risk by the 45 not being street workers. It’s a variable within your control.