Therein lies the devil.

How does one debug a houseful of 'smart things' that sometimes work and sometimes do not?

Where is the balance going to be between having more of these things and having more troubles precisely because you have more of them?

Will we require a 'smart things monitoring service' just to keep it all working and advise on what to do when it does not work? Who will create and run such a service, and how will they be paid?