In countries with multiple languages its generally expected you speak them even if most do not.  If anything the question perhaps we should be asking is why so few Canadians are bilingual.  I've travelled to over 40 countries and I've been to multiple ones where the majority of people are able to speak more than one language.  In Europe, knowing a second language is the norm and if you are unilingual it is generally frowned upon that you are uneducated.  Also there are other jobs with such requirements.  You want to be an air traffic controller anywhere in the world, you must speak English and this applies even in countries where very few can speak English.