1.....is the best reason IMO. Why carry a tire plug kit and air compressor? So that you are prepared just in case you need it.
Yes I hear you, my best friend in Canada, I will keep the details short, went down the wrong path early in life, had a BSA 650 at 16 years old, was over 6 ft tall, got involved in a , I will call it a motorcycle club. He was in a apartment, one night his brother , who had a key, figured it was better to crash at his older brothers place rather than drive the 30 miles home in blowing snow. Well he entered the apartment around midnight, came face to face with a 12 gauge pump action sawed off shotgun, luckily his older brother recognized him.
So I have never heard of a compressor or tire plugger killing anyone accidentally or on purpose. Need is a loose term, you confront a grizzly, pepper spray may just piss him off, unless you speak grizzly chances are you aren't going to be able to talk your way out of that situation, that is when you NEED something really big and hope your shaking and aim can be coordinated before buddy Grizz takes his shot.