Comment by donovanm

It has nothing to do with job hoppers deserving more money, it's more that companies don't typically pay those who stick around as well. The job hopper would be more likely to already be making more money, therefore he'd have more leverage going into negotiations. The likelihood that you'd spend ten years specializing in something that is exactly what lots of companies need at the moment is fairly low, especially in an industry where the churn of technologies is high. It's more likely that they'd have ten years experience in a dated technology.