This hasn't been true for years. The emulator shipping with Adroid Studio uses an x86-based image, and it's very, very fast as a result.
Android's emulator even has quite a few more features than iOS's simulator, such as mock camera scenes so you can even develop apps that rely on the camera on the emulator.
If anything these days the Android emulator soundly trumps the iOS simulator on all interesting metrics except maybe RAM usage. But, critically to Linus' argument, they both use the same architecture as the development machine.