[anko]

It's also that sometimes they stay on that codebase because they weren't the best engineer, and all the better ones move on to bigger things.

[hyeomans]

Or they were the best and the ones who left were the worst ones. The argument can be made both ways.

[decafninja]

Or they are a junior or expert beginner engineer that thinks good code means checking off as many design patterns as possible. I've seen this a lot.