Since actual real-life autopilots nearly universally don't act that way, does that not mean it's a perception problem?

If people are dying, then it's a people dying problem. If the number of people who die depends on what name Tesla chose for the feature, then Tesla is at least in part responsible for the people dying problem.

If I'm a bartender, and I tell a customer "this is a strong pour - it's literally cyanide!", and the customer drinks it, there is not a "he should have known the right definition of literally" defense.

So far it seems to be safer, not more dangerous, than regular driving.

I would argue that we do not have conclusive data. If Joshua Brown had his wife and kids with him in the car the simple math everyone is doing (fatalities / miles driven) would not look so good for autopilot. It's going to take a lot of miles before we know for sure. Probably 100x what they have so far.

In an abstract academic sense, maybe. The fact is, that's what the vast majority of people think autopilots do. You can either spend billions on ad campaigns and such and still probably only reach 10% of the market over the course of a few years, or you can just call the feature something else.