You are right. The OP's examples of networking, SQL, etc. are NOT the foundations of computer science. I know as I did my undergrad in actual foundational CS theory.
Here are the foundations of computer science: Sets, Boolean algebra, integers, strings, functions, logic circuits, iteration, recursion, proof by induction, loop invariants, automata, regular expressions, context-free languages, Turing machines, computability, asymptotic complexity, data structures, algorithms, NP-completeness, models, formal logic systems, operational semantics.
But to agree with the OP, a lot of CS graduates may not have learned or have forgotten the mathematical underpinnings of CS. A typical bad "CS" education would be some hodge-podge of algorithm design, hand-wavy analysis, and teaching specific technologies/tools (e.g. CSS, NoSQL).
Here are the foundations of computer science: Sets, Boolean algebra, integers, strings, functions, logic circuits, iteration, recursion, proof by induction, loop invariants, automata, regular expressions, context-free languages, Turing machines, computability, asymptotic complexity, data structures, algorithms, NP-completeness, models, formal logic systems, operational semantics.
But to agree with the OP, a lot of CS graduates may not have learned or have forgotten the mathematical underpinnings of CS. A typical bad "CS" education would be some hodge-podge of algorithm design, hand-wavy analysis, and teaching specific technologies/tools (e.g. CSS, NoSQL).