I always smile when scripture comes in handy... in the 21st century.
There is a relevant didactic passage about only those without sin to throw
Most regulars, if not all, seem unaware of their own off-topic postings, just
because they have posted on-topic in the past. Meta-discussions about off-topic
posting are off-topic themselves -- Surprise.
Analogous to the quantum observer effect, a poster cannot moan about the
abundance of off-topic posts without increasing the number of them, if his
post has only moaning and groaning. It's like pissing against the wind.
Act accordingly, folks.
And instead of those whining posts write something medieval and help YOURSELF.