You could just as easily spin that to "If you don't know enough to not believe, you are theist." But rather you focused on only half of what I said.
Sorry to but in but I have recently solidified my position on this topic.
What you are arguing is akin to a Christian stating that they are a Christian but not a theist.
You might be missing the point that these are simply 'hit on' categories, you are not required to identify within them.
But whether you identify with it or not is irrelevant, the definitions don't lie.
Agnosticism is a category of atheism, just as Islam is a category of theism.
This is one of those situations where you're arguing a set point, like complaining that the Earth is round.
You can say whatever you want about the Earth not being round, but that will not make it any less round.