GP is not talking about JS frameworks, though. They're talking about layout constraint systems (the argument goes that CSS is harder to reason about because "width" might not mean physical width, since it could affected by margin, etc). The counter-argument, of course, is that there are many more types of devices now (e.g. using "desktop" experiences in an ipad, multiple screen resolutions, etc just to give a few counter-arguments to the notion that desktop is "simple")

As for frameworks: the market has indeed spoken, but not in the way you think. Consumers of websites rarely pay for the majority of websites they use. Employers, however, pay developers and the buzzword-chasing in resume building/interviewing cycles is real.