We have a college grad who volunteered for one of our COBOL/assembler teams. The kind of alpha nerd who runs his own reverse engineered WoW server, that kind of thing. So it might seem surprising that he's want to be buried in COBOL-land, but his rationale was pretty simple: he wanted to come to work, build things, and go home without being on a treadmill of learning new crap all the time.

That was a decade ago. He comes to work, he churns out business functions, he goes home and fiddles with whatever amuses him. Meanwhile the grads in the same era who came into .NET or Java teams have gone through how many patterns and frameworks? .NET to .NET Core + .NET to all .NET Core, WPF, UWP, whatever the new hotness is? J2EE, SpringBoot, microservices, JSF, React, React Native, etc.

I find it hard to think he did the wrong thing, really.

No because we don't tell them when recruiting. Lol. It's because we only need small percentage to know it and they get to work on other stacks.