To give a summary. Everyone interested to consider reading the sequences won't be able to spot much that he/she doesn't already know or that seems unique. The people who Less Wrong would help the most do not have the necessary education to understand it.

I disagree strongly. Using myself as my only data-point (flawed, I know, but deeply relevant for me) the exact opposite is true. I had enough education to understand (nearly) everything (some of the more advanced math took extra study to follow). But I had never been exposed to such a large amount of concentrated sanity in writing. The greatest asset of LW wasn't that it provided education I didn't have, but rather that it provided sanity I'd never been exposed to. That made a huge difference.