Agreed that there's a signal among those who decline to dump their work history publicly into the hands of the largest company in the world and its recruiter flock in exchange for maybe job leads. It is eccentric, unfortunately.
But reading that signal partially will filter out improperly. Aside from privacy, candidates who value their time don't want to be disturbed unless they have initiated.
Someone whose LI profile doesn't exist (or has just 'go to my site') is more experienced at the game.
