The bureaucrat, not having a personal stake in the security of the keys, will be more lax than an individual. No one believes that agents of the government will look out for them as well as they look out for themselves. If they did, perhaps we'd all be happy to let the IRS compute our taxes. It would sure make life easier. But we don't.
Individuals are always the best protector of their own interests.
To hammer on the point, there have been repeated cases of INS employees selling green cards, FBI agents creating rules of engagement later found unconstitutional, and agents of every three-letter agency in Washington selling out to the Russians. The point was perhaps most succinctly made by an NSA historian who I spoke with at the NSA museum. If we mandate backdoors in a system, they will be found and exploited. Give end users control of the technology, including source code and access to algorithims, and they are empowered to choose a level of security that is appropriate. The government can not do so, and should not try.