I'm in agreement here. I've set up PGP email, and S/MIME, and it isn't really that hard to use once it's in place. Mail clients that support it offer easily-invokable "sign" and "encrypt and sign" options. But when few people you email use it, you yourself end up using it rarely, and then you get a new computer, lose your keys, and you can't even revoke them because you didn't keep a backup. So you have to do it all over again. Then it seems "difficult to use" because you have to stop and read some man pages again.