The "culture of quitting"
Here's an interesting article called Up or Out that talks about how people whose careers have stopped progressing should just leave with no hard feelings... and how this is already the case in legal and accounting firms (ie. if you don't "make partner"), but for some reason doesn't seem to happen in IT organizations.
He even refers to employees that leave happily in this was as "alumni".
This is an interesting point of view, since most people are more obsessed
with increasing the quality of their workforce through hiring rather than
firing attrition. For comparison, see "hiring above
the average" at Google.