I read it as "95% are bad, so its not worth the hassle in the hope that you end up with one of the good 5%".

I and most of the people I know have received all of their jobs through conferences/meetups, word of mouth/direct referrals etc and I find that much more pleasant than dealing with linkedin and phone spam. I do still maintain a LinkedIn account though.

I am now cofounder of a startup and, despite my LinkedIn profile clearly stating this, I still received messages from recruiters about jobs.