I don't think hackability is so much the point as open ecosystem, privacy, and interoperability. iOS wiped the floor with Symbian, and Android wiped the floor with iOS due to being more open than the predecessor. Linux is the most popular OS kernel in the world (think routers, smart devices, etc.)

I want a choice of thermostat which fits my decor, and for that to work with my smart thermometer. I'd like to buy both on eBay from a Chinese company if I'm poor, or at an upscale designer store if I'm rich.