I first came across a similar technique expounded in a book by Chaim Potok, "The Chosen" (good book, I really enjoyed it).
One of the protagonists, Danny Saunders, was the son of a rabbi and a genius who was trying to become a psychologist, so he started reading Freud in its original form. He found the texts impenetrable even after months of trying.
Then he had an insight: in the study of the Torah (his forte, being a rabbi's son), folks typically studied with the help of commentaries by rabbis over the generations who have disputed and explained the texts in different ways. Commentaries provide context and a jumping off point into the text. So Danny Saunders took the same approach to studying Freud -- instead of reading Freud, he studied commentaries on Freud and read what has already been said about him. This helped him understand the original work better.
Many of us do the same instinctively: we read the Wikipedia article on a subject to get a lay of the land before jumping into a subject matter. Context is valuable in pedagogy, which is why it's often helpful to have an instructor for reading hard books -- otherwise anyone would be able to read any book in their language and "get it" -- which is not true. I read English just fine, but I don't think I'm able to understand Finnegan's Wake without any help.
p.s. We often hear advice that we should study texts in their original form without commentary, so that we can approach the subject with an unbiased lens and interpret it for ourselves. But my take is our lens is always biased, and worse still, in subject areas we are unfamiliar with, our biases are uninformed. I think a much more productive approach is to read with commentary but to read critically -- to question and to explore alternative interpretive options. Without this kind of approach, most important works are just too difficult and we'd probably just not try.
So commentary and criticism and analysis and so on can serve as a useful bridge into the way of thinking that you'd need to really grok the primary source. It's probably impossible to get there completely, there will always be a bit of a gap. But the more secondary material you read, from as many perspectives as you can find (I do think this is very important, in addition to the critical thinking mentioned in the parent; even a very critical thinker, in a strange land, can be deceived into believing there is consensus on a matter when presented only with a single side), the better chance you have at being able to focus the center of the thing, with all the various lenses you've been given.
At least, the center of it relative to your own set of biases!
I've always been interested in reading the Great Books, and some say the only investment you need is a library card, but it's not that simple. If all it truly takes to read the Great Books is just reading them, a lot more people would be doing it. But they're not. Having taken a sequence of courses on Western civilization, I realized there's a lot more to reading the Great Books than just reading them -- most of the time is spent in footnotes, commentary, research (to understand context) and of course, arguing with the text. Otherwise all you're doing is streaming words into your head.
It's all in English, but it's also like a totally different language.
And you're on point about critical thinkers being deceived when they don't have the full context -- Sherlock Holmes says to never theorize without data, which is all well and good, but sometimes your data can be incomplete in ways you cannot detect and you end up developing a perfectly coherent model of the world that is fatally wrong. This is often a problem when you theorize within a single work. Having more context from different sources doesn't fully solve this problem but it does mitigate it.
Articles are usually written with an expository focus rather than a didactic one. Sometimes an article is so abstract that I don't get it until I read comments on how people are applying it. (it all depends on the quality of comments of course. No comment on the quality of HN comments) Comments also give you a sense of the sociological context of something -- articles can sometimes make something sound grand and theoretical, but sometimes you discover in the comments that the author had much humbler motivations and was just trying to scratch an itch. Or that a piece of tech with a glossy front page actually has all these gaps because the author is a one-man shop who is working on it part-time.
Social context really matters. In grad school, I realized there was a difference between what you read in a journal publication and what the author will tell you after 2 drinks at the bar. You can read influential and highly-cited journal papers about Algorithm Zeepordisdf which sounds really impressive, until you meet the author at a conference and they tell you no one really uses it because of this and that weakness. It's important to be able to read between the lines and to read around a subject than to just read the source.
Though Gladwell sort of surrounds the topic with the stories rather than doing a front-load as this strategy suggests. Still, I do feel like I remember a lot more about Gladwell's books compared to others.
How do I know what story/books surround X without reading X first?
More, how do I know what books surround X without reading those books first?
Skimming subject literature, asking others, googling (someone's probably talked about it before), wikipedia, even flipping through X etc. are all useful. Subject areas rarely exist in a vacuum.
A big part of education is learning how to learn things -- it's a metaskill. Knowledge exists in a network, and knowing how to use the network to bootstrap is a tremendously useful skill.
"First we tried to figure out the properties of matter, then this whole 'atom' thing started making sense, then we figured out about subatomic particles, then we realized that subatomic particles actually act pretty weird -- so that's quantum mechanics."
If you were to just start at quantum mechanics, you'd wonder why the heck everything is so weird and overly complicated.