Does drain plug washer is really required to replace every oil change?

[dr. d]

Makes it very easy for crazy people to pull a prank ...

hard to tell whether the car has a stopcock or a bolt.

meaning to destroy an engine by draining it of oil, is not a prank.
and if they really want it, the wrench is almost as easy.

stealing the spare tire is probably just as easy, and more profitable, too.
heh heh.