I'm not terribly clear about what the assumption is, exactly, and I'm not sure everyone in the conversation has the same referent for it, so rather than say "yes" or "no" to an ill-defined question, let me articulate some related thoughts.

• I like the idea of fanfiction where characters who in canon think and behave in muddleheaded ways and ignore what seem like fundamentally interesting aspects of their world instead think and behave clearly and attend to the interesting things.

• If done well, rationalist fanfiction can be a great example of that, as rationality is a very useful tool for focusing one's attention on the things that matter. I like that sort of rationalist fanfiction quite a lot. (Which is not to say that I like anything that qualifies as rationalist fanfiction.)

• MoR explores some marvelous ideas, it's clever, it has moments of genuine humor and genuine human feeling. The early chapters, in particular, really spoke to me; the later chapters less so. As fanfiction goes, it's probably in the top 10% of what I've read in my life, not that I'm a huge follower of the genre. But it has weaknesses that frequently bug me. As fiction goes, I would be fairly disappointed if I'd picked it up at a book store. I don't care too much about Americanisms vs. Britishisms, though.

• I'm vaguely intrigued by the LOR variation -- it reminds me somewhat of the Sundering novels -- and might read it some day when I have more time to spare.

Dunno if any of that is relevant to your discussion. If not, feel free to ignore.