Comment by belorn

The primary argument in favor of TPM's is the desire to assert against tampering to the boot system, and as a secondary effect it can be one of the solutions to reduce the need for users to type in passwords.

You can still use crypto without a TPM, including with full disk encryption, and for LUKS specifically you can use multiple passwords and mechanisms to unlock the system. Different solutions will give different benefits and drawbacks. Me and a friend wrote a remote password provider for Debian called Mandos which uses machines on the local network as a way for unattended boots. It does not address the issue of tampering with the bios/boot loader, but for the primary purpose of protecting against someone stealing the server/disks it serves the purpose of allowing us to use encrypted disk without drawbacks of typing in passwords, and the backup server, itself with encrypted disks, handles the risk of needing recovery passwords. At most one needs to have an additional backup key installed for the backup server.