Utilitarian logic does have some major downsides, Solaris, as you say. On the other hand, even the founders of Utilitarianism envisioned its use *within* a society, as opposed to imposing it upon another society, and they themselves saw the downsides and worked on ways to limit negative uses of it (and the classic one was by establishing a set of ground rules, which could not be violated because they were absolute rights... yes, this is where the whole concept came from, and why).
Where you have a philosophical problem is that you are envisioning a particular set of rules that apply to your society, taking an extreme position on them, and then imposing those rules on societies where that extreme position on those rules is not accepted. Specifically, the right to unlimited free speech. It's an extreme position, because it does not exist even in the USA, and yet by assuming it to be an absolute right and refusing to allow any compromises on it even in other countries where it is not assumed to be an absolute right, you are demanding that it be imposed in every other country in the world. By what right do you demand this?
(Yes, I am playing devil's advocate here)
Where you have a philosophical problem is that you are envisioning a particular set of rules that apply to your society, taking an extreme position on them, and then imposing those rules on societies where that extreme position on those rules is not accepted. Specifically, the right to unlimited free speech. It's an extreme position, because it does not exist even in the USA, and yet by assuming it to be an absolute right and refusing to allow any compromises on it even in other countries where it is not assumed to be an absolute right, you are demanding that it be imposed in every other country in the world. By what right do you demand this?
(Yes, I am playing devil's advocate here)