Reading on, he's not perfect, though (I mean, what is? again - very few things are simple, and anyone who suggests something is should be viewed with some suspicion, in IMO!) Interestingly, there's also this in the list:
“Despotism is a legitimate mode of government in dealing with barbarians, provided the end be their improvement.”
And there's the rub - the conception of certain groups as barbaric. Again, going back to human pack mentality, I think a society defines itself more by who and what it isn't, than what it is (it feels like there should be a word for this?) And so to validate itself, it must in-validate the Other.
This is, again, an indication of how desperately important the open exchange of ideas is, though. I think it's arguably fine to in-validate the Other by first understanding, and then, in so doing, meaningfully opposing their ideas. But in not even making that attempt, there's an implicit presumption of the Other's own "barbarity" - ie. their incapacity to so much as formulate their own ideas or to reason at all, and, as such, their lack of what makes us human; of humanity. Ad hominems like some of those we see levelled at so-called "TERFs" above implicitly dehumanise them in this abstract sense, at least (is ad hominem then a misnomer?! 😁)
I do see that kind of characterisation in the OP's posts in words like "hate", "diatribe", "zero thoughts", "rush to" etc., and the resistance to engaging. It conceptualises people who are actually sharing thoughtful ideas - even if the OP finds these ideas hugely problematic - as merely emotional and instinctual, ie. lacking reason, uncivilised, barbarous etc.
I think perhaps Mill makes the same mistake in his generic characterisation of some peoples as "barbarians", although I guess the lack of shared language and imperialist context made it harder for even the best thinkers of his time to breach that gulf of understanding.
We don't have those excuses.
NB. Thanks (and sorry!) if you read this far. Could be waaaay off the mark with Mill. Kind of just thinking aloud.