This applies to many non-fiction best-sellers in the self-help and pop science categories, but is very unfair as a generalization about non-fiction. (And bloat is not restricted to non-fiction, either: do we really need 10,000 pages of Wheel of Time or Stormlight Archive?).
I'm looking at my bookshelves now and see great books like Ryan's "A Bridge Too Far," Peltzold's "Code", Hodges' "The Enigma," Koestler's "The Sleepwalkers," Churchill's "Marlborough." None of these feel "bloated" or "padded" (okay maybe "Marlborough" is a little bloated). None of them were written to convey a handful of ideas to make you look smart at a cocktail party. Surely the information in these books could be condensed, but that condensed form wouldn't produce the same experience.