A short but very informative thread.
Now I understand why it was hard to get immigrants to speak French. The French Quebecois by its nature were not very assimilative because of the strong association they had and maintained to Catholicism and (New) France. So the only ones who managed to assimilate were Irish and a few Scots. Even the Italians who were traditionally Catholic ended up "going English".
This reminds me of the situation in Malaysia where a lot of non-Malays still have a relatively poor knowledge of Malay despite its being the national language.
Malay language in Malaysia is very strongly associated with Islam and "Malayness" which are almost synonymical there. I.e. even if you're of Chinese or Indian descent, you become a Malay once you convert to Islam.
This contrasts with Indonesia where the Indonesian language (which is basically Malay) is seen as a language without any association with a certain religion or ethnicity.
Most people growing up in Indonesia regardless of their religious, ethnic or even linguistic background end up speaking Indonesian.
It's interesting to see this parallel between Quebec and Malaysia. Many a Malaysian actually prefers speaking English to a fellow Malaysian because of the certain neutrality the English language possesses.