No, the people trying to prevent working-class solidarity that sold the idea that a vague upper-income segment of the proletariat with no clear or coherent definition, and none of the type of differentiation in fundamental relation to the economy that defines an economic class, are the “middle class” in capitalism rather than the classical definition in which that is the petit bourgeoisie were the redefiners.
If you want to redefine middle class to be small business owners and merchants that don’t depend on a salary that’s fine I guess, but that’ll be an even smaller percentage of the population than the modern middle class.
And remain so, yes.
> Most people were peasants.
No, most people were working class. And remain so.
> Is that what you’d prefer society to be like?
No, that's what capitalism is like. Redefining the upper income class as “middle class” is an effort to preserve capitalism by dividing the working class against itself, which I oppose because I’d prefer society not be like that.
But, more: I'm a "worker". I work for other people. I also make a borderline-top-10% income. I make more than many small business owners. So I'm not middle class, because I have a job? Class is about how I get the money, not how much money I get?
And in your last paragraph, you talk about "the upper income class". Is there one class hierarchy that is based on income, and another that is based on source of income? If so, why should I have solidarity with my income-source group rather than with my income-level group? And if not, then what are you trying to say in your last paragraph?
It's a historical use still common in some contexts. I agree that being clear on the definitions being used is important, including marking explicitly where definitions may be different from what the reader is familiar. But it's not a definition dragonwriter has simply invented.
The Wikipedia page on middle class has more info.
In the USA, an alternative definition has become popular, where middle-class is like the middle section of a bell curve.
No, it didn't.
If you are salary-dependent, you are working class.
A slightly higher than non-Hispanic white median salary used to mean you were in a relatively comfortable, but still wage-labor-dependent, segment of the working class. Women entering the work force in mass and some other changes, it takes a slightly higher multiple of a single non-Hispanic White median income (but a fairly similar multiple of a non-Hispanic White household income) to do that for a household, and its been that way for most of the working life of Gen X and later.