There's an irony here: practices like meditation make us more aware of this constant unsatisfactoriness, but they also make us aware of the crucial distinction between the mental faculties that notice sensations (e.g. itchiness, hunger, jealously) and the faculties that react to those sensations. It's like the author learned a great deal about human mental life but didn't go all the way.
Pain and suffering, for example, are not the same thing. Suffering is a reaction to pain. And one can train oneself not to suffer, or at least to suffer less. Likewise, one can train oneself to have a greater appreciation for love, pleasure, and good fortune — to really "lean in" to positive experiences emotionally, so as to get more out of them.
So for someone to make a great sweeping gesture with their hand and say that life is a wholesale terrible experience is merely to betray that person's ignorance of how experience works in the first place.