Words have meaning.
I think that's actually one of the significant issues that I'm bringing up. what are the meanings of these terms and who decides them? What does it mean to have condition X, when condition X is ill defined, constantly changing, or defined differently by different groups of people?

Words certainly have meaning, but only within a specific and particular context. Deciding what contexts are the most legitimate is one of the questions that I'm trying to raise with this post.

Distorting their meanings to suit whatever fantasy you are wanting to live out today debases that meaning, clouds communication and is in general a very bad idea.
I certainly think there's value to this notion. I question the appropriateness, often, of some of the people that call themselves "plural" when in reality their experience is hardly even remotely similar to DID. I think the mental categorization concept can be useful, and I do think there are dissociative conditions that can result in something a lay person might describe as plurality, but these are not DID.

Once again, the issue comes back to: Who defines the meanings of those concepts?