Since someone can only be logged in to one character on an account at a time, it really doesn't make much sense to disallow players who already have a character on a server from making new ones. If they are logged in as their main or a bot, it still is only one logged in character.

The queue to login, lag and whatnot results from the number of people logged in at once-- a good number of whom are bots or are afk. I know nobody liked the afk timer, but I didn't see anything wrong with it. And I sure as heck am in favor of bringing the pain to the bots.