I have recently started to read Letsrun. I have enjoyed getting to know it thus far. Without getting into the moralities of freedom of expression, there seems to be an issue of a conflictual and evolving identity. Which is energetic, interesting and multifaceted compared to what happens in printed media, bound by stiffer parameters. And intensified, with respect to pre-web era publishing by the fact that readers are potential and likely contributors on the message board. This would not have been an issue in non-interactive times. But now the volume of information generated by the readership could in theory surpass the volume of information generated by the publisher. All in the same "printed" space.
So I don't know if it is jealousy as much as people with a common-name interest - running - which is undergoing a major second-phase growth and possible re-definition, finding out if they can be reasonable "thought-mates." Personally I treasure frank discussion and can endure hard criticism. Others could be fragile.
By chance, I read Karnazes' book. I would not be surprised if beyond the sports and outdoors categories, it was placed on the self-help shelf in some bookstores.
People think they become runners. I would like to suggest that (not considering the obvious exceptions) we humans always were and are runners (as opposed to lacrosse studs or ballet primadonnas and other learned movement practitioners.) Everything else, competition, local, regional or international, training, solo feats, guiness records, charity, fundraisers and what not, these are just abstractions. Running itslef is not an abstraction. We are born with it inside.
Not that what I learn should be used as a benchmark, but simply stated, I have learned useful lessons from several and different running humans as I suspect are to be found on Letsrun. Including the juvenile or juvenile wannabees who as thread-said, practice, as threadly-defined, trolling.