i can see where you're coming from with driver responsibility... but i do feel its not right to set a 50mph speed limit, and then no warning of a 90 degree bend when the road is not lit. when you're on a road that is set at 50mph, you don't expect a 90 degree bend.
you are correct in stating if it wasn't that corner, it would be another. This is the case... don't get me started on the next one 100 yards away (which turns 90 degrees the other way). This one looks like a T junction, when in fact the road turns left with a "right turn" that looks like its going straight on... many people have shot straight across it without realising. The only solution here, i feel, is to change it to a T Junction, but that's another thread! LOL As it happens they've usually scared themselves shitless on the first bend so are already being more careful.. but there's still the odd one that either carreers across or ditches themselves here too..
but anyway... like i said, roads that this speed limit don't usually have what is practically a dead end. This is why, for once, and once only, i'm on the side of the driver.