How are MORE bad examples an argument against what he says? If anything they reinforce his statement.

Plus, the thing with "tar" and "ls" is that they've been tar and ls in all Unices for decades. If you learn "ls", and maybe "dir" if you want to use Windows, you're golden. Whereas every language seems to use its own names for "princ", "setf" etc, both before and after CL.