[xorcist]

You don't have to master it. But some things are just well worth learning at least the basics of: Your programming language of choice, your shell, your editor, your version control system.

An afternoon learning your way around bash or vim will save you countless of hours of work, just because you will know what the building blocks are, you will be able to ask the right questions directly instead of chasing down alleys.

It's not the same thing as learning yet another language. It's a separate type of tool. Developing software without knowing an editor or a shell is like refusing to learn what a file is or what an ip address is. Sure, you can probably get work done in roundabout ways, but it's certainly not rational.