You've clearly never met a person who is unable to place a hanger inside of a shirt and hang it on a rack, or a person who can't sort 5 single-digit numbers mentally. What you are describing are 120+ IQ problems.
An IQ of 100 is defined as the median IQ level for a population. The range between 90 and 130 covers the whole gamut of human intelligence that's commonly considered normal.
Much of the day-to-day work in IT often doesn't need original thinking but merely skillful application of known methods and patterns, which in turn doesn't require a college education.
Point proven, eh? I'm not talking about these people (though I surmise there are quite a few in these companies as well who don't have that level of intelligence and simply tag along ...) but about the vast majority of IT workers working on some supposedly 'boring' database application.
Google and Apple in particular have been known for hiring highly qualified engineers only to then have them maintain some run-of-the-mill administrative software they're vastly overqualified to work on.