The parent made an appropriate comment in my opinion. Twitter as it exists today is in the public sphere, it is not your living room. You are shouting something throughout the net and invite everyone to share their opinion on what you said.
We should all be old enough to understand that the world is full of morons whether we like it or not. And if they are part of your community it becomes your problem too. Dont want to be confronted with the unpleasant parts of of the twitter userbase? Dont be on twitter.
If you however want the reach of twitter without any of the downsides, to bad. Make up your own platform with your own user guidelines. Twitter offers such a huge reach because everyone gets to comment whether you like it or not. You might like that or dislike that, but your opinion on it doesnt change the current atmosphere on twitter.
If you use twitter as it exists today, you better have a thick skin. There are no two ways around it. To exaggerate, you would also need a thick skin if you wanted discuss the topic of migrant rights in some neonazi club. Sure it would be awesome if they behaved, but not something you should expect as a reasonable person. And if you wanted to have a positive reasonable discussion, why would you ask them in the first place about their opinion?