From an employee's perspective, rather than contractor, I feel that it's fear that keeps me on LinkedIn.
"What if I lose out on an opportunity, or seem strange, because I'm no longer on LinkedIn?"
"What if I lose out on an opportunity, or seem strange, because I'm no longer on LinkedIn?"
If I ever end up in a world where it's only possible to get a job using LinkedIn, I can probably recreate my profile, along with contacts, and recommendations in a week or so.
Clients from LinkedIn in are way more high maintenance on average compared to StackOverflow/SE and GitHub. Maybe it's not as bad for recruiters.
good luck.