In general, you can expect all the good ambitious people to leave. The ones who stay are those who think they can stay and play politics better, or have a "beaten wife" mentality that they think is loyalty, or are on a visa.
EDIT: A previous boss of mine was unhappy I was quitting, and apologized that he couldn't give me $40k in cash to stay for another year. Me leaving meant they needed to search for a new, qualified person, and then spend the time training them, which was certainly close to $40k of time-money. Unfortunately, upper management didn't care.
EDIT: A previous boss of mine was unhappy I was quitting, and apologized that he couldn't give me $40k in cash to stay for another year. Me leaving meant they needed to search for a new, qualified person, and then spend the time training them, which was certainly close to $40k of time-money. Unfortunately, upper management didn't care.