I explained it already...
Put yourself in the officers shoes...
You pull over a vehicle at night...you cannot see into the car, it is dark, at any time you can get blown away...sure 9 times out of ten...it will turn out to be a routine traffic stop and the driver will be some housewife in her 40's...no problem.
The one time out of a hundred...it could be some idiot that is out on parole...he just drank some booze...and he swears he will never go back to prison...
The officer has no idea if THIS traffic stop is the one where the convict is pulling out a weapon from under the seat to blow his away...so THIS is why they draw their weapon...because they do not want to be the ONE cop that nonchalantly walked up to a car without his weapon ready and got blown to .
This is the reality of policework. I am not paranoid. This is police procedure ..which no-one ever thinks about....they just get pissed when they see a video and a cop shoots a kid and the kid happened to NOT have a weapon...well...the officer THOUGHT that the kid pulled out a shiny metal object from his waistband...and in the split-second before he could confirm that it was a gun....he shot and killed...and the kid was only pulling out his cell phone, enraging all the cop haters to call the cops dirty and the shooting unjustified.