Well how many Real Life conversations do you know that don't swing from topic to topic? Yes you may start out talking about Workplace Safety but the topic might shift to fishing or that really hot redhead your wife let you shag while she was in the hospital (*).
So if that's the way Real Life is, I don't understand why some forums get so fucking bent out of shape if a topic drifts.
I think it's more like Alpha Nerd syndrome. Here I am "Geek Of Geeks" running this forum telling all you other lesser non-forum running Geeks what to do and how to do it.
TrekRPG.net used to be the worst. So was the cancer forum that my wife eventually took over before our server crashed. Practical Machinist can be rather strict in some of the subforums.
(*) true story
Science can sum up the universe like this:
REALITY = STUFF HAPPENS
Religion sums it up like this: REALTY = STUFF HAPPENS BECAUSE GOD MADE IT HAPPEN UNLESS WE DISAGREE THAN SATAN DID IT.