I'm a french communist and I wish to discuss this question here because the french forum is closed.
Not to discuss in the wind, there are the texts that deal with the issue:
Parasitism and decay of capitalism, 8e chapter of "Imperialism, the Highest Stage of Capitalism" by Lenin
From 1848, a bourgeois-proletariat grows in industrial countries. According to Engels, we find this bourgeois-proletariat especially among the industrial workers and the unionized workers. Since then we can add public servants, intellectual workers and all workers who earn significantly higher wages than the average. In front of the mass of the proletariat, this proletariat is a minority.
From the imperialism beginning, not only this proletariat is favored, but it also earns a part of the surplus profits by the imperialist capitalists. So for a same work, they earn a higher (purchasing power parity) wage, only because they are American/European/Japan workers, and not Indian/African/Chinese workers. Imperialist capitalists buy social peace with surplus profits.
This proletariat is opportunistic. It allies with the bourgeoisie of its country against other proletarians (Engels) and against the bourgeoisie of other countries (Lenin). It participates in all the sacred unions, for the imperialist wars and against the civil war. It is reformist, nationalist, and counter-revolutionary. He thinks only of increasing its wages, not of abolishing the wage system. It is obviously against immigration, and for the privileges given by nationality, numerus clausus and degrees.
I add the bureaucratic rulers in USSR were bourgeois-proletariat: employees, but exploiting the rest of proletariat like a true bourgeoisie.
Why has marxist bourgeois-proletariat theory been forgotten? Because most of the “western communists” are bourgeois-proletariat, and want only to improve their “national” situation. They say: “we must not divide the proletariat”, but in fact, they only care about their national and corporate business. They yell: “Hurray! We keep a salary of PPP $2000 / month!” but they do not care about those who earn PPP $800 or less, abroad.
They replaced the marxist theory by the idealistic theory that “the bourgeoisie persuades the proletariat to be opportunistic/ nationalist/ reformist with its propaganda”. If this theory was correct, how to explain why the class struggle is much harder in poor countries such as South Africa or India than in rich countries such as USA or France? How to explain the 90% proletariat (rich) countries are less revolutionary than the 10-15% proletariat (poor) countries?
They totally forget that the bourgeois order is not protected directly through the bourgeoisie but by special proletarians: police, military, judges, etc. They totally forget that the bourgeoisie does not grant democracy only when it is sure to win the elections, either because the country is predominantly peasant and petty bourgeois (India) or because the majority of the proletariat is bourgeois (Europe). In other cases, there is no democracy.
The bourgeois-proletariat is the shield of the bourgeoisie. Sometimes it's his sword. If we want to destroy bourgeoisie, we must destroy bourgeois-proletariat. All our efforts should be concentrated in the mass of the proletariat, not in its surface which is sold to the bourgeoisie. This means in particular that 90% of resources of western communists need to be reoriented to propaganda in industrial poor countries.