This is a valid point but I have also read posts on youtube by persons who are obviously still active JW's which were also quite aggressively written. I have to say that the person who wrote it came accross as being quite stupid. I'd like to think they were just naive but no, it was more than that.
As for 1975, well...actually, yes, it is still relevant because it is an intrinsic part of Watchtower history and as such is vital in assessing their credibility in their claim as being God's mouthpiece.
After all, does the Watchtower not keep harping on about the evils of the Catholic Church? Many of which are hundreds of years old!
And if history is not relevant then how are people to learn anything about anything and why study it in college or university???
Granted, if we act in a belligerant way then we surely do lend succor to the Watchtower predisposition regarding 'apostates' but righteous indignation is not wrong in itself.
I, for my part, will never dilute the truth about the Watchtower cult.