Would you agree that LinkedIn is not "thinking for users" as others (esp.Apple) do? Basic virtue of the human nature is laziness, and it's well understood by the most successful consumer companies and inventions.
Consider TV Remote Control. Consider iPhone. Facebook...
Now on LinkedIn, the most "active" function is "connecting to people".
It actually makes me think that very soon everyone will be connected to everyone, withing their area of expertise.
Is this the ultimate goal for LinkedIn and it's customers? I doubt it.
LinkedIn is not thinking hard enough for its users. And its users, being business-oriented, have little time to actively use LinkedIn effectively.
And this is why it's not as popular as Facebook.
LinkedIn's user want to upgrade jobs. How does LinkedIn help this goal?
It helps people to connect and then relies on their actions.
As many have found out, the only reliable part of web user is inaction (well, make it a single click).
It would help if LinkedIn figured out your future job aspirations and found those jobs, and suggested them on a "single-click menu".
It would help if LinkedIn figured what people might be useful to you, and mutually introduced them (not based only on past, think "future").
It would help if LinkedIn suggested you groups to join, based on your skills and activity, and introduced groups to people, and well as people to group moderators.
Now all it does is "keeps you linked in"...