Based on my experience, it's more about the corporate structure of assigning promotions and raises.
Depending on the job, 2 years is plenty of time to get well acquainted with the work flow of a position. The jumping ship happens when someone is ready to move up, get more responsibility and more pay, but it isn't happening.
At my last job, after 6 months I felt like I had a firm grasp on what I was doing. After 1 year I was starting to get bored because the work was too easy -- I was good at it, and often consulted by my seniors and juniors. My company did performance reviews every 6 months, and only reviewed for promotions and raises once a year.
At one year six months, I met with my boss and told him I was ready to take on more responsibility. The response -- "Yeah, I'm really happy with your work and will make sure that's clear on your next performance review". Was I going to wait another 6 months? No. I jumped ship and got the responsibility and big pay raise elsewhere.
I don't think it has anything to do with abandoning a job you're not good at. It has to do with wanting more responsibility and pay. Ship jumpers probably feel like their job is too easy and that they are good at their current position, as is implied by your survivorship hypothesis. The good talent is the one jumping ship.
Depending on the job, 2 years is plenty of time to get well acquainted with the work flow of a position. The jumping ship happens when someone is ready to move up, get more responsibility and more pay, but it isn't happening.
At my last job, after 6 months I felt like I had a firm grasp on what I was doing. After 1 year I was starting to get bored because the work was too easy -- I was good at it, and often consulted by my seniors and juniors. My company did performance reviews every 6 months, and only reviewed for promotions and raises once a year.
At one year six months, I met with my boss and told him I was ready to take on more responsibility. The response -- "Yeah, I'm really happy with your work and will make sure that's clear on your next performance review". Was I going to wait another 6 months? No. I jumped ship and got the responsibility and big pay raise elsewhere.
I don't think it has anything to do with abandoning a job you're not good at. It has to do with wanting more responsibility and pay. Ship jumpers probably feel like their job is too easy and that they are good at their current position, as is implied by your survivorship hypothesis. The good talent is the one jumping ship.