Ultimately, while people may have very little trust for the government in general, the one thing that people do trust the government for is establishing identity. We use government ID papers to establish our right to work, to open bank accounts, to enter legal agreements, and to cross borders. Why should communications be any different? We don't need to trust the government with the content of the communications (and we shouldn't), by not providing the government with the private keys. But why can't I get the government to sign a public key for me?
The issue it raises is whether people will eventually get locked out of society if the government decides to get antagonistic with somebody by revoking their public key and refusing to issue a new one, given a society where such a scheme is popular. But we don't have any sort of such protection today - the government can seize your passport, seize your driving license, freeze your bank accounts. A society in which the government solves identity issues for the digital age is only a net improvement over the status quo.