I liked the star system, too. As the site grew in popularity, people just ended up 1 or 5 starring stuff.
For the same reason - the “useful content” and “not useful content” buttons were dumbed down to “agree” and “disagree” buttons on reddit.
Agree that you can’t really ask people to use a star system for message boards. Much less microblogs.
Even without the politics, the Peter Principle all but guarantees incompetent leaders.