@amszmidt @screwtape @glitzersachen @mark
If your point here is that Lisp compilers were originally more sophisticated than C compilers of the time, yes, that's my memory too.
Part of that is because Lisp compilers were on 36 bit mainframes while C compilers were on 16 bit 64KB minicomputers (and a little later, on 16 bit 64KB microcomputers), so there were definite reasons pushing towards that.
However, if you are also remembering that those sophisticated Lisp compilers emitted code that ran faster than what was emitted by those unsophisticated C compilers **in the general case**, then your memory is faulty.
C is a much, much easier language to compile efficiently. And to this day, Lisp has constructs that do not have simple fast machine code equivalents. Absolutely anything at all that is dynamic, for instance. C has no such things, aside from trivial still-fast constructs like function pointers. It doesn't even have built-in hash tables.