Another, contrarian perspective: I worked with IBM Fellows, CTOs, Distinguished Engineers, VPs, and divisional GMs for two decades, and they were sharp. Less than 1N on the CATRA scale sharp. Absolutely on par with folks I worked with Apple, HP, Intel, Microsoft, Oracle, Sun Microsystems, and IBM's competitors of the time.

IBM's approach was indeed heavy-weight, and they loved complexifying things—but so did a lot of their customers in finance, aerospace, automotive, consumer goods, yadda yadda. IT operated by an entirely different business model and set of preferences in 1960–1990 than it did in 2000. It was the bespoke, pre-open standards, we'll handle all the edge cases in this lovingly homegrown solution era. The products were expensive, but in many cases solved technical operational problems that nothing else did. "Best of breed" was a common rallying cry; interchangeable parts and the virtues of utter standardization only came into prominence slowly.

The world's very different now, and there was enormous tension inside IBM, and between IBM and its customers and competitors, evolving to where we are today. (The same was true of almost all the legacy competitors.) However real that tension, what worked in the Before Times was the cause, not that IBM only employed doofuses or brought Mongol Hordes and crappy technology to bear.