"To be blunt, even asking that question betrays ignorance."
To be blunt, this is coming from someone who is comparing an intentionally created fictional character whose very specific definition can be disproved using scientific method, to a concept that has been in existence, since before writing, appears in almost every culture in the world in some form or another, and includes abstract definitions that can't be disproved using scientific method.
"People who ask me, “why can't you just be agnostic?” generally labor under the misconception that “agnostic” means something different than “atheist”, as I myself did for many years."
"“Atheist” simply means a person who lacks a god-belief. It doesn't represent any kind of coherent, organized belief system, which is (apparently) another common misconception many people suffer from."
It is not a misconception. It can mean something different.
Agnostic: "a person who does not have a definite belief about whether God exists or not"
Atheist: "a person who believes that God does not exist"
"Agnosticism, in fact, is not a creed, but a method, the essence of which lies in the rigorous application of a single principle. That principle is of great antiquity; it is as old as Socrates; as old as the writer who said, "Try all things, hold fast by that which is good" it is the foundation of the Reformation, which simply illustrated the axiom that every man should be able to give a reason for the faith that is in him; it is the great principle of Descartes; it is the fundamental axiom of modern science." ~ Thomas Huxley
"If you self-identify as agnostic, and you don't go to church on Sunday, or otherwise lack a god-belief, you're an atheist. An agnostic atheist, if you will. The terms are not mutually exclusive."
No, I'm not an a-theist. I am actually a person with a philosophy. I don't self-identify as everything I'm not. I self-identify as things I am. If you happen to use the broad definition of atheism, you can consider me a weak/negative atheist. But, no matter how much you call me an atheist, I won't be going around calling myself one.
"Agnosticism is of the essence of science, whether ancient or modern. It simply means that a man shall not say he knows or believes that which he has no scientific grounds for professing to know or believe." ~ Thomas Huxley
"We can say we know, based on logical deductions, that a literal Santa Claus could not exist."
Well, duh. The proposition "Santa Claus exists" can be proven objectively false and the counter-proposition "Santa Claus doesn't exist" can be proven objectively true. We know exactly where "Santa Claus" is supposed to exist and, guess what, he isn't there. Absence of evidence is evidence of absence but, only if you're sure you're looking in exactly the right place. Not finding penguins in Cuba, doesn't mean penguins don't exist. So where, exactly, are people looking for "gods", and not finding any? Where are "gods" supposed to live?
"In much the same way, strong atheists say they know that no god exists."
No. A deistic type concept of "god" can not be proven objectively false, nor can the counter-proposition, "no gods exist", be proved true. Just arguing that it's a man made concept, and therefore false, is not logical. Every ounce of human knowledge started as a concept in someone's mind.
What happens if science advances so far that we find a way to replicate the science used in forming the universe? Have we proved "gods" don't exist, or proved they do? If there's any possibility of us ever being able to replicate that science, how can we claim anything proves that our universe wasn't someone else's science experiment?
Here's a question, for you: What do you call someone who doesn't believe that proposition "gods do not exist" is true?
"A much more important question is, why does saying one is "just agnostic" avoid trouble?"
Because diluted definitions leads to the trouble of having a convoluted mess of a labelling system, making communication harder...
Gnostic Strong A-theist
Agnostic Strong A-theist
Agnostic (no belief label)
Agnostic Weak A-theist
Labels are supposed to make communication easier. The more qualifiers you need to describe your position, the less effective your label is.
Is it better to have the word "chair" mean "a separate seat for one person, typically with a back and four legs", or is it better to have the word "chair" mean "anything you can sit on", and then have to add qualifiers like strong couch chair, weak stool chair, weak chair?
"It means you'll pretend to respect knowledge claims based on faith, even if those knowledge claims are completely contradictory to evidence (like the fossil record and/or radar)."
That is clearly a statement from someone with absolutely zero understanding of agnosticism, in any way shape or form. Please, never attempt to publicly describe me and my label further, until you actually know what you're talking about. If some atheists want to give themselves the a-theist label, I don't really care, but can you all please stop redefining my label, in the process, and publicly telling people the definition of agnosticism, when you have no clue what you're talking about.
"So next time, my dear agnostic friend, you're trying to save face by excluding the strong atheists in your life from gatherings of religious people, remember that you're excluding people who share your own viewpoint."
Well, no. I don't believe gods don't exist, and they do believe gods don't exist. But yes, we both don't believe the theists claim. And, why would I exclude them from gatherings? Does "agnostic" = "bigot" too?
"the agnostic argument is so pervasive, and so ridiculous, that I do not think we can drive enough stakes into its hollow heart"
Yes, faith in a scientific, or objective, method is ridiculous. Pffft. What a stupid statement. It is the best method we have for discovering an objective reality. Huxley described scientific method as fairly common sense logical deduction.