I personally didn't run into any of these mentioned issues when the Quackers were live, those I know were all on the 'You don't have to use them if you rather not' boat. I also played regularly with those who had them disabled, which nobody around seemed to mind! I liked them mostly for personally use, since I have the habit of typing out a sentence, hitting enter, then going "AND ANOTHER THING-" in my Roleplay, which has definitely led to some confusing conversations as I'm still on Point A while the other person moved to Point B before I get that other sentence out! Alternatively, I liked knowing if someone else was doing that same thing so I could get the full context before replying. Definitely a 'me thing', but I found it helped with the flow of conversation a lot and helped me reel back when I needed to so I could give opportunity to the other player.
I don't doubt some people used them to be jerks or weaponized them, and I also don't doubt that those instances stick out like a sore thumb when you see it so they're easy to remember. I'm not sure it was as prevalent across the server as it's being made out to be? Those who do that, should get reported. Another way to put it, is that we have the Disguise System, a minority of people abuse that system, and everyone knows they shouldn't, but we still have it for the benefit of what it's meant for. I think Quackers are in a similar boat, and I'd personally like to see them return as an option but not a requirement.
I certainly don't mean to handwave off those who have concerns, as they are valid, just to be clear!