Then don't read it. In several years you've made only a couple negative, snarky comments on HN.
If a guy writes an entire book and you don't want to read it because he made a spelling mistake, then don't.
If a guy writes an entire book and you don't want to read it because he made a spelling mistake, then don't.
Having said that, I'm still interested, but the lack of proofreading on the author's release announcement for his book is definitely counterproductive.