The problem is that performance for most common tasks that people do (f.e. browsing the web, opening a word processor, hell even opening an IM app) has gone from "just okay" to "bad" over the past couple of decades despite our computers getting many times more powerful across every possible dimension (from instructions-per-clock to clock-rate to cache-size to memory-speed to memory-size to ...)
For all this decreased performance, what new features do we have to show for it? Oh great, I can search my Start menu and my taskbar had a shiny gradient for a decade.