I've heard that exact same adage used in reverse by those "6-7 years at the same company" engineers against engineers with careers of shorter stints. The logic being that if you never experience 5/6/7+ years of continuous ownership, you never get to see how your decisions pan out, and you miss out on other forms of longitudinal experience.

If one thing is a constant, it is that engineers will always come up with these silly little adages and cliches to discount the experience of their peers and continue telling themselves they are the smartest kid in the room.