Programming language is very specific to instructing a computer to do a particular structure of a sequence. It's the very way you tell the machine what you want it to do.
Bell Labs was an astonishing place for many decades, though it fell on somewhat hard times during the telecom meltdown some years ago, as its corporate owner had to cope with shrinking markets.
Unix has, I think for many years, had a reputation as being difficult to learn and incomplete. Difficult to learn means that the set of shared conventions, and things that are assumed about the way it works, and the basic mechanisms, are just different from what they are in other systems.