I really don't think it's just a tech company thing, though. But, talking about tech companies, or at least my experience which is tech, but not SV, is that I

I really don't think it's just a tech company thing, though. But, talking about tech companies, or at least my experience which is tech, but not SV, is that I see certain people turnover frequently, but a bulk of the people stick around. There's an aversion to firing people (I think my word use is a bit cold) and the company is also not investing in the employees. Those people who I usually see stick around are dependable, but not always ambitious or following new things. I feel like this can lead to over-investment is old tech and continue struggling with solved problems. That over-investment in old tech can make recruiting hard, too. (I'm talking about continuing to use SVN, Cent5, or Python 2.6 when a DCVS, like git, would be incredibly helpful to your workflow--not using last year's javascript hotness instead of this year's javascript hotness). On the flip side, there was an article the other day where it showed people who moved around generally got paid way more than people who stuck around. I've been seeing this for years.