David, the problem with your position is its circular in nature. From your own quote:
"The walled-garden versus open argument isn't new. Apple's approach was great when it was used to reinvent the smartphone. It isn't so good when the company is playing catch up in a home market which is already growing without it."
You acknowledge the ongoing debate of closed/open - you acknowledge, in hindsite, the value Apple brought through its walled ecosystem. When Apple originally came on the scene, critics siad the closed ecosystem was bad for the market or would fail, neither of which occured.
Fast forward, you are claiming the HomeKit and Apple's philosphical approach will be bad - but history has shown us, the market supports both open and closed ecosystems. Often, products come to the scene initially from Anroid's side of the house and are polished through the Apple side of things. Everyone can argue the pros/cons of Apple - Android (even Microsoft) but history has shown start-ups, who do not want to play with Apple initially can find success in the Android side of the house and based on user demand (which correlates to investment dollars), Apple development can occur. Many choose to go after the Apple market first, which is fine as well.
At the end of the day, what Apple has brought and continues to bring to the table is successful. While arguable, I would suggest overall, Apple's ecosystem has helped advance the connected society, if in no other way, through shear advertising and awareness. The products rise and fall due to the own success and maturity, not becuase of Apple. Adoption of Apple's HomeKit will be about vendors choosing to tap into that devoted market segment and should be part of their business plan with regards to if and/or when to engage in the Apple ecosystem.
I, for one, would embrace the HomeKit as a formalized standard from one of the three Tier 1 platforms (Andoird, Apple and Microsoft) - a standard that allows uniformity and a true IoT to exist -- right now, I have 8 connected devices in my home and 6 separate apps to manage them - chaos for a non-tech person, which in hindsight contributed to why Microsoft's original Windows Mobile devices were tough to get adoption - they weren't user friednly, they weren't polished the way Android was when it hit the scene and Apple's iOS. Standards do not stifle innovation, rather provide fasttracks to adoption - I assure you, even with HomeKit, folks like Logitech will still maintain their Harmony platform. But others, like GE, will embrace the HomeKit to improve market acceptance of the IoT lightbulbs and other technologies.
Standards, whether by Apple or someone else, are good for the industry, especially when they are presetned as an "option" and not a government mandate.
Appreciate the review -- hope you keep yourself open to how this can actually help the industry as well.