Anyway, so I decided to start looking around to see what other people's opinions were, and I came across one mother of a thread on HTLAL itself...
The thread became kind of derailed when another user, s_allard, objected to the title, suggesting that it should be "le québécois populaire" or "le québécois de rue" or somesuch.
s_allard's position can be summarised thus:
By using the term "québécois" to describe low-status speech, Coutu makes the term "québécois" into a low-status term by association. Instead, s_allard wants to use the term "québécois" inclusively to include the "standard" language used in higher register situations. Besides, many of the features Coutu highlights are going out of fashion.
It's a valid viewpoint, but it's one that I don't personally hold. Rather, I would say that s_allard's position, while not in itself malicious, maintains an unfair distinction where one's intelligence is determined by the language one speaks. It has been pointed out that middle-class children generally do best in school the world over, but that this is simply a language bias -- school-teachers are middle-class, therefore the school lect is the middle-class sociolect.
We have a choice of action, therefore: change the lect of the children to match that of the school, or change the lect of the school to match that of the children. Academically, it's mostly agreed that the latter is the option that has proven most effective time and again, but s_allard's standpoint better matches popular opinion, whether you're talking about India, where many children are taught through the foreign medium of English; Scotland, where many say Gaelic shouldn't be taught "because many children can't even speak English properly" (for some undefined notion of "properly") or s_allard's own Canada.
Personally, it's an attitude I'd want to challenge, not least because many of the notions of "proper" English and "proper" French have been well and truly disproven by corpus studies of the language. (EG. The statistical norm in French is to drop the "ne" particle in the negative, and the statistical norm in English is to say "can", not "may", when asking permission.)
Moreover, there's the issue of words and phrases going out of fashion. I personally believe the examples s_allard gave are pretty misleading. He picked English slang words with no real history, that were invented by one generation and dropped by the next. But the "québécois" that he objects to is a historically attested form, and one that is being lost not simply due to natural language change, but by the constant imposition of the Standard French norm.
One of the books that I'm using to help me learn Corsican, le corse en 23 lettres, puts it very clearly. The author, Ghjaseppiu Gaggioli, is a descriptivist grammarian, and in the introduction states that he doesn't want anyone to interpret his work as authoritative. Instead, he wants to inform the reader so that the reader can make an educated choice. Because, he says, all languages change, but for a language to stay healthy, that change needs to come from within the boundaries of the language itself. Much of the change in Corsican today is the borrowing of feature after feature from French into the language. Similarly, much of the change in Scottish Gaelic is the borrowing of feature after feature from English.
And of course, much of the change in Quebec French is the borrowing of feature after feature from School French*. s_allard's approach leads to us defining "québécois" as something that every day becomes more like School French. He wants to differentiate the language name, while differentiating the language less and less.
Coutu's approach is more like that Gaggioli. He wants to bring people's attention to the features that exist in their local tongues, features that they are not themselves aware of. He mentions in the HTLAL thread that he gets people telling him "I don't talk like that," only to use the exact same word or phrase a sentence or two later.
This is completely and utterly normal, and anyone who has studied linguistics in a modern setting will have experienced a lesson where the teacher will tell them that "everybody really says X" and the student doesn't believe it. Over the next couple of days/weeks, the student simply can't stop hearing the phrase.
A couple of years ago, I was telling my manager about how us Scottish people hardly ever say "please" -- we go into a shop and say "I'll have a
No-one can protect their own language until they recognise it for what it is....
* I'm giving up on the term "Standard X" unless it's a statistically-defined norm-reference. A standard isn't a standard just because a minority of people say it should be. "School X" is a far more accurate term.