Here’s something from Forbes blogger Erika Andersen that says it well:

Eric Jackson, a fellow Forbes blogger I follow and find both funny and astute, wrote a really spot-on post last month about why top talent leaves large corporations. He offered ten reasons, all of which I agreed with – and all of which I’ve seen played out again and again, over the course of 25 years of coaching and consulting. The post was wildly popular – over 1.5 million views at this writing

Why Top Talent Leaves: Top 10 Reasons Boiled Down to 1 – Forbes.