>Does it magically prove I’m making a bad salary if I can’t afford my employer’s product?
Yes, if the entire premise of your employer is "here's the cheapest hot food imaginable".
>Is a five star general making a bad salary because he can’t afford a nuclear submarine?
No, because the entire premise of the military is not "here's the cheapest nuclear submarine imaginable".
What a ridiculous strawman you set up, although you swung pretty earnestly at it, Mr. Quixote.
A better example would be Walmart, whose entire premise is "we sell the cheapest goods imaginable". Despite this, a lot of Walmart (and McaDonald's employees, actually) are on government assistance. If you have a justification for why there should ever be a society where someone working at a job that boasts "we have the cheapest shit" still can't afford their job's cheap shit, then please, be my guest.