[kevincox]

It is actually a reaction to websites doing stupid things to try and prevent password auto-fill. The sites are fighting against security in a misguided attempt to improve security, so the browser vendors added a bunch of heuristics to try and correct these situations and you end up with the mess we have.

[petepete]

Equally having to jump through extra hoops to prevent autocomplete where you don't want it is frustrating, like in admin interfaces where you might be updating someone else's name.

It's an arms race of stupidity.