The motivation for PowerShell was to have something good at both. Why switch contexts when moving from interactive use to coded automation if you don't have to?
Because the requirements change depending on which one you're doing: quick shell automation isn't the same as the kind of automation you'd use perl/python for.
And yet most of the time I see bash being used for the same kind of automation that you think is good for perl/python.
And not because bash is good, but because it is what people know (since they use it interactively) and because it is installed everywhere.
So if someone had a tool that was installed everywhere, and used interactively, that could also be used to create more robust automation tasks, that seems like a win to me.
It depends on how complex the automation is. I'd no doubt use a pipeline in places where you'd use perl/python.
As for interactive use and robust automation, Bash isn't as bad as you'd think. The reason I'd go to python is because of script complexity, not lack of robustness.
