I think we have to distinguish computer
science from
engineering here. Computer science is a branch of mathematics, where theories are developed and results are obtained that in principle remain valid for ever. Think of theories of computation and complexity theory, but also logic, probability and so on.
Indeed, the observation that some Unix utilities have their roots in the seventies misses the point in this regard. I'd say this is a testament to the success of the unix approach or whatever you want to call it. It's not really about computer science.