I have nothing against the git style subcommands, in fact I think they are great. A friendly interface would in my opinion be from the perspective of an end user. In the case if GPG the end user can have a couple of goals in mind, to encrypt, decrypt or sign data. Although you could do a lot more things, for most users those would be secondary goals. I guess the average user doesn't necessarily know about autocrypt, ASCII armor, OpenPGP packets etc. Those users would have to guess whether they need to (do I need autocrypt? Why isn't it a default?). To be honest I don't think the usage output is very bad in its current form, but as a start for something that will evolve over the years I am not so sure.