A 1998 New Yorker cartoon showed a middle-aged man smiling expectantly as the CEO across from him says, "Smith, you've been with this company 25 years. That shows a lack of ambition." Frequent job changes became the norm among talented professionals in the late 1990s, as demand for employees outstripped supply in many fields and companies aggressively recruited candidates to help fuel their growth.
Today the pendulum has swung back a bit. Too many jumps in too short a time causes hiring managers to think that maybe this candidate doesn't have the resolve to overcome problems or that maybe the candidate is the problem! Plus, an employer may not want to invest in an employee who will jump ship after a few months on the job.