TW: treats people as objective factors of production.
A balance must be struck in language used to address these - they are not the same. Where is the line drawn? The objective measure of competence across the dimension of time can be made commensurate with other dimensions through the quantifier of money. So "total output-per-cost" is the standard of productivity in general, assuming all costs such as happiness and health and civilisational welfare have been accounted for (which is the responsibility of educated bookkeepers).
Incompetence is when, given the same objective assets as their peers-deemed-competent, an agent's subjective variance detracts from their ability to hit lower (not upper) targets for production.
Disability on the other-hand SIC is when objective assets are deemed to be lacking in the agent-deemed-disabled. Thereupon, affirmative action occurs when the objective asset-base is actively equalised for the agent.
Where does this lead us? It then appears that in order to reclassify an incompetence as a disability, one merely has to reclassify a subjective issue as an objective issue. This has two consequences of note: all incompetence can be reclassified as disability, one, and two, the ultimate consequence of a program that seeks to eradicate disability through affirmative action ... must require every agent to surrender their subjective traits to an objective standard.
Well that is the ominous borg-like future I so look forward to. However, meanwhile, we can simply amuse outselves with this:
1. Only some, but not all performers are incompetent,
2. whereas everyone is disabled, in some yet to be determined way.