you didn't explain how it's fundamentally flawed because you keep viewing it as something else.  in his philosophy before you apply it to the capitalist mode of production. the value of the commodity or tool is the inherit labor that is put in.  when it's applied to the capitalist mode of production is simply a point being made that inherit value a worker offers to a capitalist is their labor. what else does a worker have to offer? sea shells? shiny rocks?  also i do work a "real" job.
Canada