Exactly. Optane is basically nothing more than a motherboard version of a hybrid drive, where the hdd happens to be an addition. If that module fails, the hdd is right back to being a hdd, no longer a hybrid, data will be a pita to recover, if it even is without corrupted files since many users don't have a regular schedule of external backups. And that's not even talking about just how integrated the Optane is to the mobo/cpu in general. If the Northbridge fails, toss the board, you just lost pcie. Of Optane fails, how will that affect any other storage, is everything shunted through the Optane or is a Sata drive separate and Optane can be ignored/disabled.
MC was removed, Southbridge gone, Northbridge now pcie, even motherboard graphics are on the cpu instead. So Intel decides that it'd be good to throw on the mobo something as sensitive to abuse as cache ram. Which the system already has plenty of with the system ram especially those running 16Gb who could portion it out for that purpose.
If Optane was modular could be removed or replaced like regular ram, that'd be one thing, but hard soldered to the board I feel is a mistake.