There are many reasons why DRM is useless to the 'unpub'.
1. DRM doesn't protect a product.
2. A writer who enforces DRM / protectionist IP while marketing their work on the internet will only antagonise possible readers.
3. Physical analogies do not work when it comes to digital products.
4. File-sharing has been shown to improve sales rather than take away sales.
And the most important reason is the simplest of all.
If you write for love, then you may make money as a side-effect. If you write for money, there will never be any love.