Would you have known that everyone else had been calling it the continuum fallacy all that time? No, you wouldn't - you'd think Yudkowsky was uniquely insightful.
Furthermore, you wouldn't learn anything beyond the limits of Yudkowsky's knowledge, or - more importantly - that there was anything beyond those limits.
The habit of neologism makes stuff impossible to look up, and creates the illusion that this is new ground, not old, and that there isn't already a world out there.
su3su2u1, debating this matter with Scott Alexander (Yvain), sums up a lot of their problems with the world view (which I am as familiar with as anyone who doesn't actually drink the Kool-Aid can be, having been on LW around four years and read not only the Sequences through twice but read literally all of LessWrong through from the beginning twice), which I largely agree with as a summary: https://storify.com/lacusaestatis/sssp-su3su2u1-debate
I'll quote one telling bit, which points out the level after Bayes:
> Heck, there are well defined problems where using subjective probability isn’t the best way to handle the idea of “belief”- when faced with sensor data problems that have unquantified (or unquantifiable) uncertainty the CS community overwhelmingly chooses Dempster-Shafter theory, not Bayes/subjective probabilities.
Do you remember the Sequences post mentioning the words "Dempster-Shafter"? Me neither.
(And then there's the use of "Bayesian" to mean things that nobody else uses the term for. As su3su2u1 puts it: "I suspect I’d be hard-pressed to write about probability theory in a way that wouldn’t fit some idea you cover by the word 'Bayesian.'")
Yudkowsky definitely gets credit as a good pop science writer. The habit of neologism, not so much. And definitely if he wasn't into the encapsulated, self-referential world that LW builds. In philosophy, Yudkowsky is the quintessential Expert Beginner: http://www.daedtech.com/tag/expert-beginner
untiltheseashallfreethem notes in http://untiltheseashallfreethem.tumblr.com/post/107159098431... : "I think Eliezer did a great service in writing these ideas up. But they are not his ideas, and I’m really worried that a lot of people read LessWrong, see that Eliezer is right about this stuff, assume he came up with it all, and then go on to believe everything else he says." And that's a serious problem when the good stuff is not original, and the original stuff is not good.