Plus the simple fact that, by the same logic, you can try to both-sides plain murder on the ground that the murderer wants to murder (and, again, that the undertakers and coroners and such must be kept in business). Clearly, whilst every policy will have supporters and detractors, some detractions are more worthy of consideration than others.
Although your plane crash example falls afoul of the broken window fallacy: https://en.wikipedia.org/wiki/Parable_of_the_broken_window
Plus the simple fact that, by the same logic, you can try to both-sides plain murder on the ground that the murderer wants to murder (and, again, that the undertakers and coroners and such must be kept in business). Clearly, whilst every policy will have supporters and detractors, some detractions are more worthy of consideration than others.