I am not quite as extreme, I've held 13 different positions at 11 different companies in 38 years. In all but one case the change of job was my choice. (I got hired by a 'Design Guru' who proceeded to over-sell what he could do and then blame the programming staff when we couldn't deliver his Vision. He got fired one morning, 4 months later, and the entire department got told we had 14 days.)

All of my other job changes have been either been because I could get a better salary or more challenge in a new job. I eventually ended up working for a small HMO for 18+ years. I'd probably still be there, but all three of my bosses successively took early retirement and set me a good example.

When I was in contract programming, I stayed employed by the same Contract-house but I moved from project to project every 4 to 6 months. Sometimes the new project was inside the same company that held the previous contract, sometimes not. Those transitions were basically economic rather that 'personal growth' driven. When you are Contracting and you have a house-payment, you want to be fully employed, whether the project is 'interesting' or not.

Update -- corrected grammar.