So can you give yourself a reiki attunement? I think so. What you should ask yourself is: should you give yourself a reiki attunement? If you are already a reiki master, sure, why not?
But it might not be a good Idea to do it yourself if this is your first attunement; it is superior to have a master attune you. But why? Do reiki masters have a greater potential than you? That is not why.
Is this about any one person or master? No. That which carries the power of any attunement with a system has more to do with the collective energy, or morphic field, of the system itself.