Unfortunately, you come across selfish people out in the bush too.
A slow(er) vehicle should pull to the side, & let any (obviously) faster vehicle pass.
They may not see you straight away through the dust, but as tracks twist & wind, there are moments of clarity, & if you didn't have a vehicle behind you before, & you do now, let them pass.
I usually give a slower vehicle a chance to do the right thing, but if they don't, I start flashing my lights & hope they then get the message. If they don't, then I just stay back because I don't believe in taking any risk on lose dirt & (usually) blind bends.