First, I assume that you're pondering if there should be a rule or mechanic that only allows one character at a time. I'll make my comments based on that assumption and if your question is purely philosophical, you can disregard them.

CF is a game. The only reason people play is because they enjoy it. Every time a rule or code is introduced for the purpose of stopping people from doing something they want to do, there should be a VERY good reason to do it. As in something is badly broken or is causing the playerbase to leave. We have many such mechanics/rules in the game that were implemented because IMMs wanted players doing more of X or less of Y, and in every case it made the game less fun for the group of players that had to change their behavior. I don't mean like OOC permas running around spam summoning/bashing everyone to death. Something like that needed to change perhaps.

Here's one example: IMMs closed Galadon as a choice for a hometown a long time ago because they wanted to spread the players and, hopefully, the action to the far corners of Thera. I don't know all the reasons behind it, but all it did was make Thera seem empty even when there were lots of people on when compared to before the change. But the biggest problem is that they were forcing people, who log on to enjoy themselves, to do something they do not want to do. Stupid idea. Before you could pick a different hometown, but after you were forced to. Just because. It wasn't done to make it more enjoyable to the player, because it didn't. Tons of people picked Galadon for a reason. They wanted to. The IMMs should focus on ways to make people want to play CF more and enjoy it more, not ways to make people play the way someone else wants them to.

I play more than one char. I play CF way more than most people. When I'm bored or burned out by a char I don't want to delete, I can play another one. If I cannot, I'll go mow the lawn. We need ideas that will make people play more, not less.