Ahm.. I'm not quite sure I followed what the last question was?
That many registered accounts isn't necessarily a bad thing, nor is it unexpected.
Putting aside the members who have multiple accounts (a great many do), it is common on any gaming site for users to register, and then fall inactive after some time. Seeing that we gain 100-300+ new registered accounts each day, it's kind of a neutral matter.
Any accounts leftover do remain there, should the owner return. So, after three years of this (two of these years with registration open 24/7), I'm not surprised at all of those accounts sitting there in the server. They'll be used and played on, or if they are inactive for a very, very long time (a year and a half, I think?), then they may be cleaned away to make new usernames available for new players.