People pay for their characters and have every right to keep them logged on for every picosecond the servers are up. If you want to, you know, not spend money on your electric bill by logging off your character, I think.... logging off your character could work.

Now, I wouldn't be opposed to an autolog feature like in FFXI, which had different choices (KEY WORD: choices) for idle times until the game would shut down by itself. You also had the choice to turn it off altogether. That'd be fine by me.