I think it's ok for words to take on new meanings over time. To some degree, language should be allowed to evolve with the societies and cultures that use them. However, I think there's an uncanny valley here. I dislike that "quantum leap" has come to mean "huge step forward" when quantum has traditionally meant incredibly small (although the word itself means pertaining to quanta). Quantum was used to describe the incredibly tiny because at those scales you start dealing with discrete quantities. I agree with the use of "quantum" for small things, but I dislike the misuse of the word to mean the opposite.
I commonly use "cool" to mean popular/trendy/etc. I understand that it developed that meaning from "cool personality" as in someone that doesn't become hot-headed and explode. Someone who is calm and collected. If a word is used because of a clear and meaningful descent from an existing meaning, I can accept it. If a word is generated from a misunderstanding of a concept, I cannot.