In practice there seems to be a ton of correlation between people who say things like that and people who think their Fiat 500 stops like a garbage truck.
D: "Dad why does everyone honk at mom when she drive's us to school?"
F: "Because she drives too slow sometimes."
D: "Why doesn't she speed up?"
F: "I don't know. She's always been like that."
D: "I tried saying people are waiting for us to go [referring to a pretty benign yield right-on-red near their house]."
F: "How'd that go?"
D: "She didn't listen!"
I don't know why but it was absolutely hysterical to me. Kids are precious.
Visibility is poor and you cannot safely go through a bend at 50+ mph when you cannot see what's beyond it. There might be a stationary vehicle, a horse, a cyclists, even a pedestrian and you wouldn't know or be able to stop in time. This is how lethal collisions happen in those roads.
Yeah you know THE ROAD not what might be in it this morning.
I've heard before about setting speed limits using percentile studies of people driving on the road, which in the absence of some specific safety concern (which then needs engineering like narrowing the road or adding turns) makes the most sense.
I also wish there was more of a culture of pulling over if you don't want to drive at the flow speed. If I want a leisurely drive and see someone rapidly coming up behind me, I'll happily pull over and let them pass. There seem to be these sociopaths or self-righteous jerks who will happily drive 5km/h under the speed limit with 20 cars behind them. This is way more dangerous than speeding and should be treated as such. If you just want to drive slowly, why would you want the stress or a bunch of angry drivers behind you.