This was a pointlessly fluffy article that can be summed up with: "Flat design is a fad. Just like modern and postmodern movements have come and gone in art — so will this."
Well, of course movements change, so you could write an article as soon as a trend starts that its "dying."
More importantly, human-computer interactions is a relatively new area of design. How do we know that flat design will actually be just a fad rather than a paradigm shift?