"...a defection rate from the party line of colossal scale."

On these comment pages, that MAY be true. If so...so what? Not sure it means much. 
"Any idea what is going on here?"  Ans: if anything IS going on, not me. And, I suspect, not you either, Doc.

This much I do know: 6-day Print and Digital G&M readership: 6.6 million. At best, that's just 18% of the adult population of Canada (35,300,000 minus kids under age 15; source: index Mundi, Canada demographic profile, 2016.)  

But wait! That assumes 6.6 million DIFFERENT readers over 6 days--and that's illogical, so it's likely just--I dunno,  half that number or 9% of the population? 

But wait...that isn't really valid, either, because we're only talking about readers who post comments...how many of the 9% is that?  (and you can't count reactions, because that would include negative reactions, and so...

Well, can we say then, that the number is really small.  So, "colossal scale" of defection in your mind only, Doc.