Scripting is becoming more and more important. With everything from computers to networks going virtual, installation is becoming an API call, not a "walk to a rack/desk/whatever and plug it in" call.
If you know how to script, you can automate those things.
In a few years I can't imagine a system administrator being able to keep their job and/or compete with others if they can't script.
There is an exception, of course: People that do desktop/laptop system administration and general in-office IT service. However those jobs are turning more and more into the equivalent of working at a mobile phone store: helping people is basic equipment problems and customer support. Those jobs pay less than half what a sysadmin normally gets paid.
So... do you want to change jobs to one that cuts your salary in half, or lose your job completely when someone that does know how to script replaces you?
It's your choice.
I don't see how a person could be a Unix/Linux admin for any amount of time and not know at least basic shell scripting. I was initially driven to learn out of pure frustration with tedious commands and it just spiraled from there.
I can't really speak to the Windows side of things but I imagine there are at least some parallels.