If your Roomba misses a spot in its daily vacuuming 
  routine, it’s not a big deal. Alexa may mishear you once 
  in awhile, but usually we chuckle at the funny 
  interpretation and enunciate more clearly.

Odd choice of examples. A lot of the criticism I've seen of the Roomba is about its random vacuuming pattern which is guaranteed to take forever and still miss spots. Many people don't use Siri/Alexa/Google voice search because it's so inaccurate, and if you have to repeat yourself then it's no faster than entering the search directly on your phone.

I think Siri is a great example of this. I've had it fail to work enough times that I simply don't think to use it, despite its improvement over the past year or two.