That is indeed a ridiculous statement. Many of us who stayed at one company for a long time (my case, 28 years) were in many positions over the years continually learning (and teaching) new things.
I have also spent long tenures at a company or two, and also took continuous self improvement seriously. And yet I can think of plenty of people I knew 15 years ago who are focusing on the same kinds of problems and technologies today that they were back then, who have fallen victim to the sweet lullaby of the comfort zone.
