But do you not realise that if this race can speak why on earth is it avoiding a multi-cultural environment safe from danger. So if it doesn't attack humanoid creatures why can't it live in a city.
Maybe because Giants don't like the other races due to eras of mistreatment. Your logic is very simple-minded and has been this entire thread. It's like the Orcs living in strongholds, back in Daggerfall and before, Orcs weren't even allowed in cities and were typically attacked on sight. Orcs were enemies. Perhaps one day, Giants could possibly become part of civilized culture, but for now, they are not. It adds variety, mystery, intrigue, and realism. Maybe the Giants just want to be left alone.
With that said, I am sad we can't talk to Giants. They are intelligent and they are obviously capable of speech, as they are the ones who named the Dwemer "Dwarves" first.