Ask HN: Why didn't Amazon put a Zxxx hub into echo?

Anyone have any thoughts on why Amazon didn't put a Zwave or Zigbee or whatever RX/TX device into the echo. I suspect the cost would be very minimal for hardware. SW non-trivial but definitely do-able. Now I need to go out and buy a full hub for a tiny piece of silicon that Amazon could have included directly in the echo itself.