Those questions would be stupid to ask for a Python position, unless there was some need for working with C APIs. Why waste your time and the developer's time?
Much better to asking about relevant things; some common Python library, or why they'd use lists vs. dictionaries vs. sets, or what a generator expression is.
Allow me do disagree. Tomorrow you're going to have a project that uses a different technology, what are you going to do then? Fire everyone and start hiring again? Of course you need at least a few people on your team who know your current technology in depth, but you probably want to make sure they're they understand the basics.
And please note that those questions are not some intricate C specific questions. Memory management is a basic thing (I'm not talking about actual memory allocation algorithms, just things like how to make sure your program doesn't leak). Linked lists are also basic data structures. It's not asking what "volatile" keyword means and when to use it.
How about you need your people to make an iOS 4.x compatible app. Oops, suddenly they need Objective C including all its memory management nasties. This is going to be so much harder if you have never seen pure C.
Well then obviously you'd want someone who can deal with C. "DeepDuh" indeed.
But you're talking hypotheticals - I can do that too: if you suddenly need big data then "Oops", you're going to want someone who knows Hadoop or Erlang. If you need to launch a rocket then "Oops" you're going to want an aerospace engineer. But if you're looking for a web dev, then C/Hadoop/Erlang/Aerospace questions are largely a waste of time, and might disqualify candidates who are otherwise fine or who could figure out C given a couple of days.
Bear in mind that the original topic is talking about languages for learning how to program, not languages for iOS development. If iOS apps float the beginner's boat then by all means learn Objective C; their enthusiasm for the field will probably overcome their frustration with C. But I suspect they'd be better off learning Python or similar first, then starting on C.
Hence my original response: it depends. Python is a pretty good choice because it can do well in lots of different fields and is easy to pick up.
Much better to asking about relevant things; some common Python library, or why they'd use lists vs. dictionaries vs. sets, or what a generator expression is.