[mc-lovin]

>Not getting a wage equal to your productivity at the margin may be considered exploitation in several schools of microeconomics. If an employee provides value X and receives wages X-10, the amount of exploitation is 10.

And this is, by definition, the competitive wage in neoclassical theory. Suppose there is a group of employers, and a group of employees, and each employee adds value X to any of the employers. Then any employer will want to hire all the workers for themselves, if the prevailing wage is X - 10. So competition ensures that there is no exploitation in that sense.

So while neoclassical theory does allow for "exploitation", it also predicts that it is very unlikely to actually occur.

You seem to be reinterpreting neoclassical theory where "marginal value" is decided according to your accounting rules, rather than the competitive market.