These arguments are all irrelevant as I never argued that anyone's freedom to express said views should be impeded. I was merely arguing that Reddit should not allow it.

Freedom of speech and expression is a moral right and a human right, above and beyond the fact that it is a constitutional right. In fact, the way that the Supreme Court of the United States currently interprets the right to freedom of speech hinges heavily on something like a belief in free expression as an independent value. Here is Section 1 of Amendment XIV:

All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.

You'll notice that this clause doesn't say "states need to guarantee freedom of speech" or "a republican form of government requires that a state constitution protect freedom of speech", or anything like that. But the judicial branch has decided that "liberty" and "due process" do not here refer to what liberties and due processes a state decides to grant to its citizens, but to the concept of liberty or due process, which necessarily includes liberties and rights of the sort that the Bill of Rights forbids the federal government from trampling.

That's a bit to the side, but I hope you understand that redditors can believe that free speech is a moral value above and beyond it's inclusion in the constitution of any particular nation. You can't just say, "Oh, you have free speech, but Alabama doesn't have to allow it" or "You have free speech, but your employer doesn't have to allow it." The concept of freedom of expression is broader than a right enforced only against the national government.

I think of offensive subreddits, on reddit, and offensive groups, books, pamplets, etc., in society at large, as the canaries in our coal mine. Are you familiar with the expression? Miners who worked in coal mines would carry canaries with them. The canary is more sensitive to methane and other toxic gases than a human, so it would die before the humans noticed a problem. At that point they realize they're in serious danger and can react before it's too late. So long as pointlessly offensive speech that has no redeeming value exists, we can be sure that an institution is not permitting free speech for strategic reasons (that is, because it doesn't have the power or the desire to strangle free speech), but out of a principled commitment to freedom of expression. Once those go, then we will have no other warning until the institution strikes out against a form of speech that we do think is valuable.

The German poet Heine said "Where they burn books, they will burn people, too." This has proven unfortunately prophetic. Groups that ultimately value human rights and liberty have nothing to fear from a free and frank discussion, and will find that sunlight is the best disinfectant for fringe ideologies. Groups that do not value human rights or liberty and expect to rule by fear and terror generally start by bullying their most controversial opponents, then they intimidate opponents who are merely unpopular; next they institute censorship, and then begin to burn the books that have already been printed.