"If you own a company that employs people, you are upper class."
Tons of people own companies where they employ people, but still put in 50 hour work weeks and bring home less than $100,000 a year (or worse) without growing the company's value. In this discussion's context, I would put the staff engineer making $600,000 way ahead.
Owning cash is still asset ownership. Owning a failing business is not necessary better than owning hundreds of thousands of dollars. Plus, owning stock is still business ownership.
The quantity of ownership is important, otherwise any American with an invested 401k is part of the owning class.
I prefer the distinction of: "If you need to work to live, you are the working class". Though even that falls apart when talking strictly about income, as different people use their money differently. One person may turn $200,000 salary into early retirement while another lives paycheck to paycheck until death.
That said, I’m not sure how to fix it. The point really is that it isn’t a better vs worse score or something. Hypothetically the staff engineer could be blowing that $600k on… I dunno, I can’t imagine how to waste $600k a year, boats I guess, and not end up with the assets.
It is definitely an extreme case, though.
If you derive your income from ownership, you are upper class. If you derive it from the value of your work work, you are working class. In between we have a class of people with high-value professions and/or assets such that they are basically able to make their own employment decisions without any real discomfort. Merchants I think were the go-to historical example, I’d put highly paid contractors in that class nowadays. This class is literally the class in between the of the other two, aka the middle class.
If you own a company that employs people, you are upper class.
If the boss (maybe the person contracting you) asks you to do something unethical or dangerous and you tell them to get bent with 0 worry as to your next paycheck, you are middle class.
If the former scenario happens and you consider doing the bad thing because you’d rather not be homeless, you are working class and should probably think about forming a union or something.
Depending on your expenses, you could be middle class at 90k and working class at 600k, but if I was working class at 600k… I’d look into getting my expenses under control…
Often in the US we say “middle class” when we actually mean “median income.” It isn’t great.