Especially the lack of separate compilation units was a weak point of the original Pascal, as also noted by Kernighan. This was fixed later in UCSD Pascal (1978) and of course by Wirth himself with Modula-2 (also 1978).

But that said, it's strange that Kernighan wrote the above article ("Why Pascal Is Not...") in 1981, i.e. three years after the introduction of UCSD Pascal and Modula-2.

Does anybody here know the background of that article? Why was Kernighan feeling the need to defend C against a 13-year old language which was already not in use anymore in its original form at the time the article was written? Was C under attack and risking to lose its popularity?