Why not? It's not that hard and there is nothing special about it. Essentially it's an attempt to introduce consistency into interfaces they design. So people c

Why not? It's not that hard and there is nothing special about it. Essentially it's an attempt to introduce consistency into interfaces they design. So people could learn and rely on certain colors, shapes and behaviors for certain things across many apps they use and use them intuitively. Of course there is some evil there too, like branding and being inconsistent with other platforms on purpose, but it's in everything they do these days.