Being an original writer is a hard thing. Not only because it takes way too much self-discipline to be done in a handwave, but also because of how literature works.
You see, there are only so many ways of writing something. After a while, all of these ways are likely to have been explored and put into use. After even more of a while, these ways will be formally acknowledged by the formations of genres, with their own conventions and variations upon themes. And after the longest of whiles, these variations upon themes will have been turned into the stock examples of how to write we know from the world around us.
In short, if it can be done it most likely has been done. Which puts the ambition of becoming an original writer into a new light - the very structure of literature works against you. And you not only have to compete with the words not doing what they are told, but also against every damn writer ever.
And there's a lot of them, to be sure.
Which is why I'm not all that fond of the myth of originality. Not only because it sets the bar for entry higher than it really needs to be, but also because it's not what the readers really want. As the case of the ever more formulaic pop songs or movies show, the attraction is not in the iconoclasm but in the adherence to those predefined conventions.
I am even less fond of the notion of unoriginality. Over time, the probability that two authors independently of each other writing something very similar approaches one. Not because they lack originality, but because that's just how writing works. And there's always bound to be someone, somewhere, who some time ago wrote something similar to just about anything. If you search long enough, you will find it.
This becomes somewhat of a problem when any given author is accused of being unoriginal. What does that mean, other than that the author writes in the same world that we live in?
I'm hard pressed to see this as a bad thing in and of itself.