Many people who are perceived as "acerbic" are simply direct and don't engage in the poo-pooing that characterizes many human social interactions. To get rid of them is to revert to a less intelligent form of life.
Even if you're brilliant and correct, a tactful approach to persuasion/discussion is virtually guaranteed to yield better results than verbal blunt-trauma. Unless the goal of life is simply "To be correct", which honestly strikes me as a fairly depressing end game compared to the other options.
It's all degrees of asshole-ism, perhaps.