I think it should also depend on what kind of projects you are working on. If you work in a middle sized to big company, you can change teams and positions easily. You are likely to change them within 3 years. If you work in a small shop, you are unlikely to change the team (since there is only one) or position (there are not that may of them). Most startups fail within first few years and I would not blamed a coder who worked in startups for changing jobs as the old company ceasy to exists or changes into pure hell.
Once you hit the job that really really suits you (say you like algorithms and this job occasionally needs some), you are less likely to move no matter how experience you are already. While you are on positions that are meh to you, you are more likely to want change soon.
Of course you don't want company stucked with only people who are new there nor only with people who never worked elsewhere. But then again, company should have idea about which position requires more stability or how many of each type is there already and factor that in into decision process.