Oh that's right, on the internet, speculation and having opinions is a big no no, and is considered the eighth deadly sin.
Having opinions = bad karma
Having opinions is not bad. Throwing your opinions out there as if they are fact is bad.
Especially when you phrase things in a way that is so blatantly meant to rile people up.
Example:
"I dislike the government and I do not like where I think the Government is heading" Opinion. Using the word "think" instead of "know" as an admission of speculation. It leaves things open for debate.
"The government is bad! It's turning people into mindless sheep who don't have the ability to defend or think for themselves!" Opinion, but stated as if it is fact and phrased in such as way as to create conflict. It insults anyone who disagrees with the statement by implying that anyone who is not in agreement is a "mindless sheep". Which immediately eliminates any debate possibility.
Now, my example is not 100% comparable to the letter, but the letter does use phrasing that is meant to cause upset. It reads less like a letter expressing disappointment to dragoneer and more like a "call to arms" for people who are upset. It uses very strong language (not foul language, but strong. Words that hold heavier meanings and the like) and has a underlying layer of self righteous intent.
If it was meant to change anyone's mind or bring light to any issue, it did a very poor job of it.
It references past events, but doesn't give any information as to what actually happened in those past events.
They talk about how patient they were in order to create a feel that they are some kind of upstanding person, to make readers think higher of them, to try and make their opinion seem more credible.
It uses a lot of speculation to back up opinions. And even makes implications that Dragoneer is not a
real furry anymore.
Of course, they may not have been aware that this is how they were writing, it would not be a stretch to think the person honestly feels this way. And it would not be the first time that a person got up on a soap box and spoke like this without realizing how what they are saying is coming off. People who are upset tend to get this way.
The letter is, of course, going to sound very appealing to anyone who agrees with the opinions stated. And they are going to stand up and hold it in the air like "Here! Here! This is it!" It just gathers the like-minded together and alienates anyone who is not in agreement.
Now, I will go ahead and say that this is interpretation, this is what I gathered from the letter. I am not alone in seeing this in that letter.