Yes, sure, clinging on to certain kinds of unrealistic expectations, in certain contexts (particularly personal relationships), can be fatal.
But this is a truism that any idiot could tell you - and in this case the post is generalized to the point of meaninglessness.
Suppose you encounter someone who is openly racist, dishonest or technically incompetent at their job, and no one is challenging him about it. Because it's bad to have expectations about public & professional behaviour, and even worse to actually impose them on others!
Here's the core message: when the world isn't how you think it should be, don't have the courage to try and change it, or to speak out about how you feel. Suppress your feelings, accept everything just the way it is, and - just as long as you yourself behave well - all the bad energy will go away!
Sounds to me like someone trying to justify being a total wimp. Like someone who's so afraid of experiencing any degree of anger or disappointment that they philosophize their way to vapidity and numbness. And I'm afraid that's my overall impression of people who embrace "zen" as a lifestyle paradigm, (rather than just a mindset for, say, a discrete programming project, for which it can work wonderfully). Zen has its place, but taken too far it becomes morally corrosive, and turns personalities to mud.