Does the answer change if employable is taken to mean worth hiring to do some low level work under supervision of someone who is genuinely competent?

I don't know. My imagination is impoverished, and I can't think of anything that your basic Linux poweruser is useful for that doesn't require more advanced sysadmin chops.

That makes me hesitant to combine learning linux through Ubuntu and Python. Is that a reasonable hesitancy?

Python (and most FLOSS languages) work best under a Linux, so it's not unreasonable. It's more reasonable than learning it under Windows, for example.