I've re-read Politics probably every six months or so over the past 10-12 years. Many times a piece or point in there will jump out in a way it hadn't before; sometimes new clarity comes with time and revisiting something you thought was familiar.
I believe that Self is misreading Orwell's intent by obsessing over Orwell's advice regarding things such as similes, brevity, or words with Anglo-Saxon rather than Latin roots. Writing at its best is really just the process of organizing one's thoughts and ideas coherently, in order to communicate them effectively, with as little lost in translation or parasitic motion as possible.
The examples of poor writing provided by Orwell in Politics should remove any mystery. Orwell was concerned primarily with meaningless deconstructivist burbling, as well as propagandistic writing. He felt, rightly, that language should convey meaning, and honest writing should reveal rather than conceal the writer's intent and meaning. Too often cheap erudition and baroque sentence construction were employed for the opposite purpose, to conceal either an unwholesome intent, a complete lack of meaning, or the incompetence of the writer.
The goal is not to encase writing style and vocabulary in an "acceptable" box; in fact, I suspect that Orwell felt very much the opposite. There's nothing wrong with new coinages, new rhythms, new ways of elucidating one's thoughts, so long as it's with clarity and purpose in mind.