The perfect recipient would still have to be sent backdoors from many creators. Many more people would be handling the secret, each one a target to be social engineered into handing it over. I imagine when a more typical backdoor is made, very few people even know it exists let alone know the key to open it. Mandate backdoors and everyone knows they exist so more people will work to find and crack them. They would be very high value targets. Once opened, a backdoor would take a lot of work and expense to be closed, if you even know it had been opened.