Uhm. Private key mode is not (generally) used to encrypt data, so no worries about data loss.
It's used to make your machine 'uncloneable' and prove it to a remote party. It can be used for DRM (so you can view content only from uncloneable authorized devices) or to make sure that if your server is stolen you can make it unusable for the thief. We actually used TPM for this exact purpose - to make servers with medical data secure against physical theft.