Can You Be TOO Adaptable?

An instructor I was observing while leading a class gave the group a quote: "If you don't stand for something, you will fall for anything." It made me think about how I, myself, tend to be really adaptable. I find that most highly sensitive people are. It's probably something we picked up while trying to blend into a not-so-sensitive world. It's a muscle I'm proud to have developed. BUT - when is "adaptable" simply "weak-minded" Is that even a thing?