„Telling”. Right...
Considering left-handers were forced to use their right hand not that long ago* that comparison might not be what you're looking for.
Also, how you're told something matters.
I mean sure, killing sprees are a tad extreme a response, but that doesn't change that the right (wrong?) phrasing can make any statement abusive.
*Fortunately before my time.
Though the phrasing „use your good hand” when greeting people might've come up on occasion.
Mostly confused me, because I was using my good hand.