A few years ago, before I bought a Nintendo for my kid, he was playing Minecraft on an iPad. I tried to pair a Bluetooth controller, and had no luck. I think the OS was too locked down. At the same time, I could connect a Bluetooth controller to my Android phone and play Minecraft with no problem.

In fact, I've said for a long time that I wish I had a nice Android tablet with a Tegra chip that I could both use as regular tablet and as a game system.