are basing your conclusion on something you know nothing about. Only an idiot does that.
Actually, I know quite a lot about this subject. That doesn't necessarily mean I'm not an idiot, of course. Why are you so angry on this topic?
My conclusion is based on actual case studies. Unless you have sat with a group of elders and seen their reaction when they read these letters, you can't really know how they react to them. Let me tell you how: First, they read the first few sentences, determine that it is a letter of disassociation, then scan to find the "I don't want to be a member' clause, and close the book on it.
The letter goes in a sealed file. No one else sees it. The few elders who actually held the letter in their hands did not even read the whole thing. They don't have to. They've just been given permission - by the letter writer - to act in authority and exorcise the unrepentant evil-doer who penned these words, who in their collective view is acting under the direct influence of Satan. This frees them to act promptly with the authority that the writer has just confirmed.
My advice was simply not to give them that satisfaction. Force them to make a decision on their own. Perhaps it will trouble the conscience of at least one of them.
However, I do recognize everyone has a different situation. Not everyone has the circumstances, or the courage, to successfully fade. If you feel you need to send them an FU letter, that's your personal call.