Can't see it catching on widely enough
As the article says, to directly control these sorts of appliances you would need to mess about with holes in your firewall, static addresses or dynamic DNS, etc. Most ordinary folks won't want anything which needs that much hassle. The alternative, as described, is to buy gadgets that are configured via a third-party website, where the devices poll for instructions. That immediately locks you in to one supplier, who may change a fee either now, or in the future, assuming they're still there in the future.
Sure, Google probably won't go bust in the next 10 years, but we've all seen home music devices that relied on external servers to get streaming data, and when the service went titsup you were left with a fancy paperweight. Not to mention what happens when the service gets hacked & some script kiddie in China has fun playing with your central heating while you're away, so you come home to a flooded house from burst pipes in winter, or crispy pot plants and a sauna in August.
In essence, to get a level of convenience that works for an ordinary user, you're not buying Home Automation devices, but "Home-Automation-as-a-Service", and look how well the Smart Meter concept is going down.
That to me, and I suspect to the public at large, is not an interesting or cost-effective use case. Personally I'm tempted to do something myself with Raspberry Pis or Arduinos, but that's not a mass-market model. Maybe the folks buying £10m houses will be willing to pay a monthly fee for a "home management" service, but I reckon most ordinary folks will stick with a thermostat and a timer.
