That doesn't tell you anything about how good a programmer they are. I don't need to use a command line or man pages for 99.999% of my work, so I'm not going to waste time learning to use more tools.

> It's trying to weed out the people that can only work in the confines of an IDE and gui tools

Ah, so anyone who uses a terminal is superior to someone who uses an IDE or a GUI?

> I would however expect anyone for a senior role to be familiar with what is a de-facto industry standard.

In _your_ industry. As I've mentioned before, I use Perforce (which is standard in my industry).

> And source control in general is a great topic for interviews on both sides

Agreed, but asking somone to rattle off `git init git add . git commit -m"I can remember three lines"` doesn't tell you anything about how much they know about source control. Talk to them about branching/workflows to find out how much they know about source control, or let them use the tools they're comfortable with, but plonking someone in front of a terminal to rattle off some commands is the equivalent of looking for a "culture fit"