It was a strange moment in time. Suddenly, a whole new world of interfaces opened up, and a whole lot of them had to be designed, fast. No one knew what apps were for or what they were supposed to look like, but they knew they were supposed to have at least one. And to have an app, you needed an app design. Fast, before the competition could get an advantage edgewise.
The proliferation of new apps in combination with the lack of a precise vision of how these things were supposed to look, meant that a non-trivial amount of copying went into the design process. Someone made something that looked sorta kinda okay, and in the haste to ship something, anything, it would have to do. Copy, edit, ship. As time went on, it went from copies of copies to copies of copies to copies, until, at last, every app looked pretty much like every other app.
They had all turned into digital grey goo.
More longer friend see that sky? 