Is that because they know how to strum?

Yes, I understand that, but couldn't resist.

Many moons ago, I was at a backwoods (I am talkin 30 miles from electricity) gravel pit up ta Kent County, New Brunswick, Canada. Musta bin 30 geetars and mandies. No pick and nobody had a spare. Since I had a Ford pickup truck, I had a pair of tin snips in the tool box and made a pick from a Frisbee. Worked okay. And, it was a "Glow-in-the-Dark" Frisbee, so the stoners were really impressed.