1st: Restricting the set of students who can succeed in CS 101 to those who have already done extensive programming is one way to make sure the field never diversifies.
2nd: Computer science is not (supposed to be) about programming. Let's teach them how to think before we teach them how to be language lawyers.
It need not be about C, or present-day digital computers, or even anything to do with the von Neumann model.
But there must always be a formal notation for describing computations, and students of Computer Science must always learn to treat that notation with rigor and come to grips with its nuances.
Probably too they must always deal with the concept of indirection, and think about references to (objects that contain) other references.
I'll grant you, though, a language with a saner notation for describing pointers (and types in general) would be easier to learn than C, and could still be equally useful - if not moreso.
In the distributed systems world we have Lamport's work on vector clocks and Paxos, the CAP theorem by Brewer, the Domino paper from Amazon.
In other spaces we have the machine learning and neural networks, blockchain...
These are computer science, and they're certainly implemented with programming languages, but they were conceived (and often proved) independently of any implementation.
I suspect they do this to transition students to real C later... Won't that give them bad habits later down the line?
Seems like a lot of work just to avoid going with Java or Go. With Java, eschew inheritance (not a bad habit at all) and wildcards at first, and you're fine.
Why not? This variant is garbage collected, has array bounds checking, and doesn't allow C's undefined/unspecified behaviors.
2nd, sure, then pick something easy, like [any of the thousand of other languages] Don't hand them a "broken" version of C, just because it's easier.
2nd part 2... What do you think CS is if not about programming?