One reason is that OpenPGP is already widespread and you may use known OpenPGP key to establish shared secret and switch to OTR then. Another reason is that OT

One reason is that OpenPGP is already widespread and you may use known OpenPGP key to establish shared secret and switch to OTR then. Another reason is that OTR is not multi-party. mpOTR [1] was suggested by OTR authors (Ian Goldberg et al.), but I am not sure you can find at least one peer who has it installed, and it is not maintained. So for XMPP conferences you may still want to go with OpenPGP. [1] https://dx.doi.org/10.1145%2F1653662.1653705 https://dx.doi.org/10.1145%2F1653662.1653705