Here is the answer from "the writer" :)
Interesting question I think, seriously.
Do I search for validation online? I don't think so, I have enough of it around me, without having to turn to the web :).
What about tip (experience, hack, call it the way you want) sharing?
I see a lot of great posts written by really cool people around here; maybe is it also a way to try to give something back (or in your words, probably try to fit in the group in search for the reassuring feeling of being part of it ;)). This is (IMHO) the most probable reason.
I use all those tools for a long time, and discuss about it with my friends regularly. I think it is good for yourself to try to be good at what you do. Writing such articles and sharing it in the open is a way to find people having the same interests as me that I would never have found otherwise.
Hopefully, the post will lead to interesting interactions (exactly what I am doing right now :).
Can I call that peer-validation? Maybe, but not in the exact way in understood it in your comment :).
As a non native English speaker, I might be wrong but I felt like condescension in your comment. But this is probably my french nature speaking :p