@[email protected] @Nitrokey Because HSMs are used by enterprises in X.509 protocols only - like Certificate Authorities (X.509), client authentication (X.509) etc. etc.
OpenPGP doesn't make sense in a HSM as HSMs biggest advantage over regular smartcards is various specialized protocols (like wrapping key or split keys) are defined and used only in stuff that talks X.509. There are no OpenPGP protocols that utilize it because (probably) there is no demand for that...
