I do agree that one should not ignore the effect and power of emotion, I personally do not even believe that one can possibly to such a thing more than a pretense of doing so.
However, that also means taking into consideration the emotional response of people who you are targeting with your message. If the message that is to be communicated here is merely an expression of the rational frustration of the growing irrationality of the world surrounding us, then yes, expressing it in such an emotional way certainly empowers the message being communicated. If, however, the goal here is to criticize people for their decisions and choices, in hopes of getting them to think these decisions through and maybe stop repeating them, then putting them emotionally on guard is obviously not the way to do it.
And what I fear, is more people who loathe this growing irrationality and isolationism, to resort to only doing the former, which in effect, is another display of isolationism itself. Succumbing to anger and fear, is in fact, what is being loathed here in the first place. I do fear, that in our frustration, we succumb to the very same fault.