There are other reasons besides the character sheet one would not want to retire a character. loosing almost all your levels yeah, along with any perks and specialties you got along the way to boot. but there are also all the RP reasons, all the connections and memories you made with the character, those are hard to let go, even more so then levels. and as Zydana points out, what happens if you get the urge to come back? or someone has the opportunity to resurrect you?
and the reason why I say level 4 is personally myself and most people I know tend to use various available methods to start at level 4, FH may be a fast advance system, but level 0 is useless, level 4 you are at least full path.
I just think there is a lot more to consider as far as a retirement mechanism goes, and perhaps some discussion between existing high level players should take place as to why they don't start new characters. I think progress has already been made with the removal of personal income, its hard to go from making 10+ gold an event to a few copper. (yes quite a few high level players actually made that much and more) I also feel some of it has to do with our current setting.
