LW has a problem. Openly or covertly, many posts here promote the idea that a rational person ought to be able to self-improve on their own. Some of it comes from Eliezer's refusal to attend college (and Luke dropping out of his bachelors, etc). Some of it comes from our concept of rationality, that all agents can be approximated as perfect utility maximizers with a bunch of nonessential bugs. Some of it is due to our psychological makeup and introversion. Some of it comes from trying to tackle hard problems that aren't well understood anywhere else. And some of it is just the plain old meme of heroism and forging your own way.
I think this discussion is somewhat confused by the elision of the difference between 'autodidact' and 'lone wolf'. 'Autodidact', in internet circles, is generally used to mean 'anyone who learns things primarily outside a formalized educational environment'; it's possible to be an autodidact while still being heavily engaged with communities and taking learning things as a social endeavor and so on, and in fact Eliezer was active in communities related to LW's subject matter for a long time before he started LW. By the same token, one of the main things I took from reading Ben Franklin's autobiography was that, despite having little formal schooling and being solely credited for many of his innovations, he didn't actually do it alone. I doubt he would've been even a tenth as successful as he was without something like his Junto.
Some people will get more out of formal education than others, although getting things out of formal education is itself a skill that can be learned. (It seems to require an ability to buy into institutions on an emotional level that many of us lack. I saw college as an obnoxious necessity rather than a set of opportunities, and as a result got much less out of it than I could have. This seems to be a common mistake.) But I just don't think it's possible to become a spectacular writer, or even a middling one, as a lone wolf. If nothing else, you need feedback from a community in order to improve. Look at lone-wolf outsider art -- it's frequently unusual, but how much of it is good?