I rarely read non-fiction- not because I don't see its value, but because most of it fits into 2 categories:
a) Super dry textbooks
b) Things written by profesional book authors/journalists, who care more about making the book interesting and sellable, than "true", so I always have to read it with google in other hand going through claims one by one ( Guns, Germs, and Steel, to be clear, the main point does seem to be true, but many of authors arguments are just wrong). And even then, it often takes a few years for truth about the contents of the book to surface (Supposedly The Lucifer Effect)
Oh and don't get me started on all authors who write 600 pg book about issue, when at most 200 were needed, half of which has some unimportant stuff about authors life in it, trying to be more like fiction book... which would be nearly all of them? Only exception I can think of is Obedience to Authority: An Experimental View