[rebuilder]

Because the problem corporations face is pretty much the reverse of the problem at issue here. In a corporation, the only entity being protected is the corporation itself. Master keys exist to provide access to all of a corp's devices, even if employees forget their passcodes etc. The entity controlling the master keys is the entity being protected, and while having those keys compromised would not be great, the loss of data from not having master keys is a much bigger threat.

OTOH, for citizens, a master key with access to their private data is a problem. The data owner is not the owner of the master key in this context and therefore the very existence of such a key is much more problematic even if the key is never leaked to unauthorized parties.