I work in IT. Average people tend to fall into one of two categories when presented with big scary warning messages.

Category 1: They freak out and immediately ask for help, and tend to be very skeptical of anything you tell them to do until the message goes away.
Category 2: They ignore the message and YOLO it like Linus did, then call for help hours or days later when something inevitably breaks.
It's rare for either group of people to read an comprehend the message in it's entirety.

I find it really hard to believe that the average person would approach linux and completely ignore serious warning messages.

Have you met people? They do this with Windows.