Except that the four categories - 'Strong' (gnostic) atheist, agnostic atheist, agnostic theist and 'true believer' (gnostic theist) - do not lie on any type of continuum. They are a combination of two very different positions: An epistemological position (gnosticism/agnosticism) and an ontological position (theism/atheism). "Agnostic" is a useful category by itself so long as one is describing an epistemological position - when it is used to describe an ontological position between 'belief' and 'non-belief' for any subject it is no longer of any use, simply because it is a nonsense statement - it is the statement ~(p v ~p), which is a logical contradiction.
I don't care who is in whose 'camp'. I don't even know what you mean by 'allowable'. If everybody in the world turned around tomorrow and said that agnosticism is a middle ground between theism and atheism I still wouldn't agree because such a statement is demonstrably wrong.
You might not think that using words that have actual meanings is important in discussion, but I do. So long as people are using 'agnosticism' as an ontological position between theism and atheism, I will be pointing out to them that it is no such thing, and that no position exists. While people are asserting that they hold a logically contradictory position, I will be pointing that out to them, and it is likely the discussion will not proceed further. This is not me being pedantic about things, this is because until people are claiming a position that is at least logically valid, it is meaningless to try and discuss the soundness of their position.
It is not the label I object to, it is the position itself. I wouldn't care if the position was described as 'fluffnostastic'. The fact that 'agnostic', a word that has a real, meaningful definition, has been hijacked with this nonsense is just another unfortunate happening - not my main issue.