Here we can discuss the differences between monolinguals and the poeple who speak more langauges. How is it different in your life and thinking? What influence has this generally? For me, to be monolingual woudl be terrible and extremely dangerous. I find it very bad to be monolingual, and I can't udnerstand why the people don't see this. Many English-speakers and french-speakers are like this, they don't care at all about the other languages.
Identity and ego are dangerous things. (And I mean ego in the psychological sense, not simply vanity and arrogance.) The reason so many monolinguals are so antagonistic to other languages seems to be the fear that admitting there's value in speaking other languages would be to admit that they are in some way lesser, or disadvantaged. It's a matter of "my identity is right, therefore yours is wrong. (Because if yours was right, mine would be wrong.)" It's a bigger problem than language, because it's the same mechanism that causes racism, xenophobia, sectarianism etc etc etc: "different bad."
Since I don't focus on speaking nor do I travel much, my main use of L2s is for reading and listening. Most monolingual people who never read or listen to non-native language media simply have no idea the different viewpoints people in other countries have, which can never be accurately portrayed through the filter of their own native language media. Additionally they have no idea, especially in the age of the internet when so many think everything is available online in their own language, of the staggering amount of material in other languages that never gets translated, let alone translated accurately. Similarly they are in no position to assess the reliability of google translate. It's like how I imagine having cataracts is, one doesn't know what one is missing until they are removed.
The racism in Europe now against the muslims is horrible. My favourite nurse is muslim and she wear the headscarf, (with glamorous clothes and shoes LOL) I think that she is from Syria, then other muslims who I know are veyr nice as well. In Belgium, the hatred bewteen the Walloons and Flemish is stupid as well, and in Flanders over 30% have voted for the racist party who want to separate from Wallonia. In Flanders you better not speak French!!!!!!!!!!!!! I agree