I still think that people are being encouraged to write longer than necessary letters. For example I was reading
this thread earlier today. The poster had written a first attempt, was advised that it was too short, and rewrote it. But (in my opinion) the result of this was that was what written sounded less sincere than the first attempt.
I know there is the "if it aint broke don't fix it" argument which seems to be based on the fact that most people who follow the "standard" advice given here successfully obtain an out of court settlement. But this is a kind of logical fallacy really - there's no evidence that any success has resulted from anything other than a letter being written.
You could say, what's the harm in erring on the overly long or waffley side... but my observation, in reading the multiple threads that come and go, is that the letters often end up sounding less convincing, the more that's added to them. But also, it potentially just wastes people's time, and/or delays them in actually getting the letter sent out.