It's a real hazard that is well known in the trades, but might not be appreciated by people who are attracted to the idea of an exotic metal ring but are not in situations where they will be warned about it. The warnings here seem reasonable to me.

There's an easy workaround -- if you're working in a machine shop or where getting your ring caught by something is a possibility, the ring goes in a safe place.

For me, before I touch a lathe or mill, the ring goes in my left back pocket. Every time.