Why aren't more college students on LinkedIn?

Do people benefit from LinkedIn? I know I have been pulling back for a while in terms of the amount of information I share about myself on the internet. I have seen that I don't really benefit from giving Facebook my data - even in terms of personal enjoyment. I have received many LinkedIn invites - they're from people I know personally and/or people I could not potentially have a career-based relationship with. What's the point?