Almost every time I've tried to read stuff a sequence post is based on I've found it boring and given up.

I didn't. I've read them all. Don't know how someone finds Jaynes "boring", but different strokes, etc.

The original sources already exist and aren't attracting communities of new leaders who want to talk about and do stuff based on them!

Phyg +1

Jaynes, Pearl, Hahneman, and Korzybski had followings long before LW and the sequences existed. Korzybski's Institute for General Semantics has been around since 1938, and was fairly influential, intellectually and culturally. They actually have some pretty good summary material, if reading Korzybski isn't your thing (and I can understand that one, as he was a tiresome windbag).

If you like the sequences, great, read them. I think you're missing out on a lot if you don't read the originals.

Simply as an outreach method, listing the various influences would pique more interest than "We've got a smart guy here who wrote a lot of articles! Come read them!" The sequences aren't the primary outreach advantage here - HPMOR is. Much like Rand's novels are for her.