Well, there is the little fact that no one as yet has been able to come up with a reasonable counterargument to the various arguments supporting the positions in the book and against your position.
Or, to be blunt: your logic fails.
Or, to be blunt: your logic fails.
No. There's been plenty of valid and reasonable counterarguments. The base arguments all rely on mental retardation in one form or another to explain it.
Look at it from another point of view. Say you're a Human (a stretch for most posters here, myself included). Now thanks to a sheltered upbringing let's assume that not a day in your life have you ever seen or even heard of someone using their hands to communicate with. Then, suddenly, you one day find yourself in Sasquatchopia and everyone around you is communicating with sign language. Now your hands are very dexterous. You can make every single gesture they're making. But because your primary mode of communication is speech, it is completely and 100% impossible for you to learn this or any other form of sign language. I mean, you're already older than 13, so your ability to learn anything is completely and utterly destroyed, and whatever other silly comments have been made in this thread in that regard. And there's doubtlessly plenty of examples of Humans who were born with a deforminity in their hands, had them cut off, or suffered some rare nerve disorder as they matured. So, clearly, it makes perfect sense that neither you nor any other Human in the entirity of existance can learn a sign language. Even though you have the physical ability to do so, the mental capacity to learn what those symbols mean, the mental capacity to associate them with concepts, and the intuition to learn when and how to use it. But you can't. Even if you were born and raised in Sasquatchopia simple because of that one Sasquatch that one time who was born with a clubbed hand, thus proving that even a Sasquatch couldn't learn to communicate through hand gestures. And here's the best reason of all: Because that's just the way it is.
That's how absolutely ridiculous most if not all of the arguments have been.