I don’t think they were misled by the name. I dislike musk and Tesla, but the use of autopilot to describe their cruise control is one of those things where they are being fairly pedantic, and, out of character for them, actually technically correct. Anyone who knows what an autopilot does won’t be misled, anyone whose only experience with the term is from the 1979 movie Airplane! (Otto Pilot anyone?) also isn’t going to be misled. Then what we basically have left are HN pedants who themselves personally got the term wrong and didn’t do any due diligence.
My question is whether you believe the term is so wildly obvious that questioning whether a tiny fraction of a percent of drivers misunderstand it is completely unreasonable. It doesn't rely on Tesla having misused the term at all and for the record, I don't think they are.
But, I don't think it's unreasonable that some of the 5% of US adults who have never been on a plane might not understand what autopilot is in aviation. I don't think it's likely that the 8.4% of US adults who score below the lowest measurable level of PIAAC literacy have a good understanding of the warning messages when you enable Tesla's L2 features, or are digging through the owner's manual to understand them. It seems unlikely that the 3% of adults with <70% IQs are reasoning out the limitations of the system from technical definitions. Hopefully the idea is obvious here. You only need one person out of thousands to make a massively dangerous system. I don't think it's an obviously ridiculous argument that one person out of thousands doesn't fully understand and consider the complicated limitations of such a system.