I think it's really hard to evaluate... but what I know is, just because people eventualy dies, CF will die earlier if it counts on vets more than newbies.

My point is: Make CF less complicated to favor new players retention. Instead of relying on personal knowledge of the game (preps, gear knowledge and game mechanics) to be powerful, make CFers rely on grouping with others players to do so; it's much more fun! And anyway, vets will always have an edge in PK from their area knowledge.

I wouldn't be surprised to learn that the majority of the good pkers are newbies from a time when CF was less complicated to learn.

Because PK is such a big part of the game, the more complicated CF is, the longer it takes for newbie to:
a) just survive PK (wich is, I agree, not too long to learn)
b) be able to kill another player without counting mainly on pure luck.

I might be wrong but I suppose that a lot of newcomers left CF because after seeing all the preps, piece of gear, areas, hidden secret passages, etc they realize the amount of knowledge necessary (understand 'time sinking') to be able to compete (and not just always be pawned by) by players like Glik or Barkrmar.

It takes a lot of time just to become a decent pker not relying on pure luck. Having to compete with players almost unkillable and who can kill you in nearly 3 rounds because of their knowledge is, I think, a serious drawback. And if they have to spend more time retrieving basics preps/gear because SuperPowerfulPlayer is full looting them just for the fun of it, no wonder why newbies go look for something more interesting to do with their time... but I might be getting out of topic here. ;)