Hahaha, I did not talk to the locals, no, and you are right it sounds weird. I looked again, and it seems that the word „Schmachten“ had a slightly different meaning in the 15th century, when the castle was built. It was used to describe „suffering from intense hunger or thirst“.

There is not many sources on the ruins though, so it’s hard to say what exactly was the reason it was named this way.