How is leaving for another job after a year 3 times, any different than going to 3 companies who happens to lay you off after a year each time (for legitimate reasons)?
How about someone who is self-employed, and gets 3 one-year contracts with 3 different companies?
I see them as all the same.
I hear lots of my friends, who are managers in companies, and/or are owners of companies, complain that they can't find or keep good people.
My question always is, "Would they have stayed if you increased their compensation by 50% ?".
Their answer, in general, is a version of "Well, I/we can't do that."
My conclusion from the exchange is, you didn't want them enough to do what it took to get/keep them, but someone else did/does.