Exactly. It's up to the phone to stop charging. Blaming the cable because it continued to deliver electricity is ridiculous.
That's like blaming the sink for continuing to supply water and overflowing your glass, when you should have turned the knobs when you were done.
What does the water faucet know???
A cable is just wires providing a supply. It's up to the device / phone to say I've had enough, and I'm closing the supply gate for now.
I'm not an electrical engineer but I'd guess it's not quite that simple. What if the phone told the charger its had enough and ****** electronics in the power supply didn't stop producing power? I'd guess there is still a circuit being made in the phone from being plugged in if a power supply were to be failing. Maybe someone with electrical experience could chime in.
I also tend to notice analogies are very seldom accurate when talking about a variety of things but that's just me personally.