"Wall of text" is usually reserved for people who don't use paragraph breaks; such a complaint is unfair on a perfectly well-formatted page. If you want it narrower, maybe make your window smaller?
I shouldn't have to make the window smaller in order to be able to read the authors post. If people find the formatting too frustrating, it's their problem as they want to convey a message to me, not the other way around.
That's what Firebug is for. :)
Personnaly I use that bookmarlet that help greatly for such pages (found it on a thread here on HN) :
javascript:(function(){var a = document.getElementsByTagName('body')[0];a.style.maxWidth=630+"px";a.style.margin="auto";a.style.padding="0 15px";})()