French should be made attractive and fun for newcomers. They should put up billboards and metro ads with definitions of French words, grammar rules, and such. There should be a national month of speaking French when everyone has to try to speak French (with no repercussions of course). Stories about things like that are what one should hear about Montreal before coming here, instead of things like "a few people are not going to be nice to you if you don't speak French, but most are" or "they remove English store front names and leave those in any other language."
You must remember that the average person in the world has about 100 IQ, and when a 100 IQ person reads an article like this one, or is the victim of the slightest case of discrimination from a francophone, he/she thinks all francophones are like that and develops an automatic rejection towards the language and the French culture.
As for the history, yes, it is sad that there was any kind of repression against francophones (or any other group) once, but most people who are alive in Montreal today (especially the ones who don't speak French) do not know, remember, feel, or have anything to do with that, so just make them want to speak French and your "problem" will be solved!