I needed a new mounting plate for my Nest Protect Smoke + CO Monitor. I was out of warranty and Google support gave me a run around saying they don't sell that part and I would need to buy a whole new Nest Protect. After complaining a bit they caved and sent me.... a whole new Nest Protect. How can you be so against providing spare parts? There are only a few required for the whole product.
It's an annoyance for them to track SKUs, it's almost as complicated to track spare parts as whole parts, and they just are not a manufacturer, but instead three kids and a dog in a trench coat pretending to be one.