This sounds very strange.
I'm using Claude (Opus 4.5 via Code) every day and it's very good with regexes, sed, awk and similar bash oneliners.
We don't know what the author asked it to do, but this smells like the problem started at least several messages before that.
To author's point: code brings me joy. I'm currently learning Zig, for no reason whatsoever other than intellectual challenge and I, subjectively, like the language. I'm writing silly little programs that nobody will ever see. It's fun.
Then I switch over to a paid project, and claude[0] another task from my backlog.
There's code, and then there's code. You can find joy in some code and absolutely want to avoid coding in something else.
[0] code using Claude