I try to avoid dbus, but I don't refuse to install it. So in my /etc/portage/make.conf I have USE="-dbus" for the general case. A few packages require it, so I have it installed. Some of those packages require that other packages have dbus support, so I have that enabled in /etc/portage/package.use. So I have the minimum dependence on dbus that I can, without taking painful steps and decisions to completely do away with it.
Come to think of it, it would be interesting to see something for dbus like apulse is for pulseaudio. A more limited, less invasive version for specific uses.