I don't see that in there -- I see where it mentions about writing blog posts is bad advice, so this may be similar. However, I don't think they are saying it

I don't see that in there -- I see where it mentions about writing blog posts is bad advice, so this may be similar. However, I don't think they are saying it is bad per se, just that it won't magically land you a job. However, presenting in front of a peer group does do a couple things. First, you have to prepare, which helps you realize what skill you actually have. Secondly you end up building a lot of self confidence, especially on the topics that you are presenting on. Which in my case somehow worked major magic. When I was last unemployed for about 4 months, I seemed to have flubbed a couple interviews. Well, I went to some Linux user group meetings, presented on a couple technical topics I was passionate about, and then offered to help anyone with problems that they were having on any of their environments (this was related to things like iptables configurations, clustering, virtualization, etc). The following week I went into an interview, and it was like I was watching myself on auto-pilot. Identifying problems and offering possible solutions, picking up on what was working or not based on body language, dynamically adjusting my message to fit what the interviewer was looking for, and I landed the job and started the next day.