For all that is lauded about flat design in this article (i.e. the benefits), there is no mention about the drawbacks. Nielsen Norman Group, who does evidence-based research on design trends, has pointed out as recently as late 2015 that flat design continues to present usability issues for users. As designers, we can agree with each other about the points this article makes about simplicity, minimalism, readability, typography, visual hierarchy, appliance of colors, quick visual perception, principles of grids, and visual balance. Yet, if clear affordances of interaction are missing and users struggle with what is “clickable” and what is not, it won’t matter how cool we make the design. If they find it hard to use, they will find it frustrating and ultimately not cool. I submit to you that the drawbacks NN/g points out in their research also needs to be taken into consideration.