> In an over-simplified world of Good Developers and Bad Developers, the Good Developers generally don't get fired or quit much, and if they do, can usually get another job through references they made at their last one. If they happen to not have any references who can get them a new job and enter the general recruiting market, they usually get snapped up quickly.

They will also get snapped even before they end-up on the open market. For college hires, might be more than a year before they graduate or accepting a full time position at the end of an internship.