But, there is no common understanding when a label means one thing to one person and another thing to another. For example, when the word or words someone has always used to define their self-identity suddenly "evolve" in the community's interpretation. This puts you in an untenable situation... how you've identified for decades is no longer valid. You don't feel comfortable with or fit with the new interpretation of that label, and there seems no other, more precise label available.
Labels are tricky. Most folks seem to need at least one, sometimes several. And, now the alphabet soup of individual community identities has become a self parody.
Now, I wouldn't go so far as my neighbor who complained to me that, "It used to be that you were either gay or straight. What's wrong with that?" Still, it's almost as if a person needs a yearly refresher course in labels to keep up.
For me, although I'm bi, queer says everything I need to say about myself... unless I'm potentially getting sexually involved with someone, in which case, they deserve to know the rest of the story.