This is what happens when you reject S-expressions as the only true form of syntax. People will keep arguing all kinds of nonsense, for the same reason that in logic, falsehood can be followed by anything you want.

Different people? Original C and Unix software projects used hard tabs for indentation, and that carried forward into the age of the BSDs. Almost all Unix ecosystem software was tab-indented until relatively recently. Some GNU projects were notable early exceptions, though using spaces for indentation was the least objectionable aspects of their indentation style, and more understandable in that context. By my recollection, it was the increasing popularity of C++ in the 2000s, which was at that time centered around Windows stylistic culture, that initially brought the proliferation of soft tabs to Unix/Linux, followed shortly by the Python community, which for whatever reason gravitated toward soft tabs notwithstanding the earlier preference (including that of Guido) for hard tabs.

It's not obvious in modern editors or code browsers, but the Linux kernel, much (most?) of the base Linux user land, and the various *BSD projects (kernel and user land) still use hard tabs for indentation.