I can only think of one a-hole who ran a league and then declined to play games in it. Anyone who does that would have a very hard time filling another league.
Lots of people just forget they are logged on; if someone is listed first in the lobby and doesn't respond, my assumption is that's what happened. Another frequent cause is crashes. When the game goes down, anyone who was logged in sometimes remains logged in when it comes back up. I'm pretty sure that happened to braveboy yesterday.