LJ doesn't have a Like(tm), +1(tm), or other such general-purpose one-click response option, so we have to, brace yourself, use our words here. This is rather likelier to involve thought, but it takes more effort--effort which people hooked on FB/G+/etc. are unused to putting in. As a result, we get less feedback here than we get on other shiny social media (even though the feedback there is ultimately less genuinely connected), so we post less here.
It's frustrating. The marketers are winning, because we are, more than we like to admit, creatures of reflex and habit, and those things are very manipulable. The only defense is mindfulness: awareness of ourselves, our instincts, reflexes, and habits, and claiming our power of choice.