I define it as an opportunity cost to learning another technology or language that is in demand in the market. In other words, my perspective is from a career building (increasing total compensation, i.e. $) point of view.
I think it's worth learning as an indirect awareness skill anyway - if you go somewhere and you can k exec into a pod (and know what that is) off the bat then that's good.
That's the sort of thing that makes people really useful - not relying on another "infra" or (sigh) "devops" person to do the basics.