There is "complex", and then there is "complicated", I believe the author refers to the latter. A complex solution involves a lot of moving parts, but each of these parts serves a specific purpose, such that it is possible to break down the solution into relatively simple, understandable blocks. On the other hand a complicated solution will have inefficiencies, some of its building blocks may be too big or convoluted to be broken down further, causing implementations that are hard to understand and/or may be redundant, feeding back into the complications. I think Rube Goldberg's Inventions are an excellent example of the difference I'm trying to make.

Social posturing is certainly largely to blame for over-complications, but I think more deeply, a lot of people hate to let go, to be told that the very thing they were responsible for, that they worked hours/days/... on isn't necessary any more, or perhaps never was. And then in the other direction, there are what I refer to as "exponential requirements", for lack of a better term. You buy a large bag of coffee that you could simply use as you go and store in the fridge. Or, you could have a jar with some of the coffee in it, and the rest of the bag still in the fridge. Then a plate to put the jar on. Then a new shelf to put those plates and those jars. By the time you've followed this track long enough, you're looking at buying a new house, even though your essential requirements haven't changed from the beginning.