I think this rant is more about Gnome than about dbus. Yes - there's a lot of Worse is better (https://en.wikipedia.org/wiki/Worse_is_better) design in there.

And yes the default and in particular the glib implementations are horrible. The sdbus implementation is way cleaner.

The claims about "everybody can call everything" are just wrong. There are bus policies and if you care you define them. That being said - the desktop people don't care. But that's not a problem of the dbus design.

Look at CORBA or DCOM. You don't really want that either.