I guess my viewpoint is that while vulgarities themselves may not be immoral, I find them to be a "slippery slope" so to speak. Yes, you can describe a car as a four letter word or whatever, but how long before someone slips up and starts using that to describe a person, or a group of people, etc. Whereas while avoiding vulgarities will of course not eliminate hate speech, it cuts off a slippery slope avenue in my opinion of using objectifying language towards a person or people.What I'm saying is that it's not the "ugliness" of the swearwords themselves that determines whether it's hate speech or not. People don't become hateful and aren't incited to violence because they hear others talk about marginalized groups using "fuck" and "shit." Swearing is not violent. Hate speech itself is.
ETA: And I'm not talking about slurs. That's a completely different and absolutely abhorrent practice that has no place in public speech. But luckily, the only time we heard the n-word for example, it was in a 20th century context in an episode about racism. Not in the everyday speech of Federation citizens.
And to be fair that may just be how I see things. For example, I don't drink alcohol. I respect that it's not illegal to drink it but all I see is something that has no real use and can easily be a gateway to other problems. I'm not equating using vulgarity with alcoholism but what I see is something that I don't see any use for, the rare positive uses of it are slim or nonexistent or can easily be replaced by less potentially harmful alternatives, and instead it just ends up a potentially needless slippery slope to worse things when that can be cut off much earlier. So I see your viewpoint now, mine is different, and I guess that's just how things are.