Right idea, wrong product?
The support problem is presumably solved by owning the distro and having automatic updates enabled.
Whether a hardware vendor is the right kind of business to own such a distro is another matter. With a little effort, it wouldn't need to be tied to particular hardware, but would need to be very tightly controlled at the software level. Since access to the distro and its updates could be protected by password/licence key, presumably there's a way of extracting money from grateful customers. Whether there are enough grateful customers to make the business viable is another matter.