Government could hold the keys. Sufficient weird behavior should also trigger release.

It is not always possible to provide the required support. First, it is expensive, as someone needs to prepare all the materials and resources the community would need to continue supporting the product after official support ends. Second, there are legal restrictions, for example, you may not be allowed to provide access to the radio firmware. Finally, most companies simply do not want to make their intellectual property publicly available.

You could make the argument that manufacturers only need to provide the means for the community to support the device, rather than extensive documentation. However, these communities are often so small that this would never be a priority for most companies. Combined with the IP-related issues, I don't think this is really feasible.