The "loser" in this post is somewhat of a straw man. How can one tell the difference between an incompetent/ineffective employee and one that might be undergoin

The "loser" in this post is somewhat of a straw man. How can one tell the difference between an incompetent/ineffective employee and one that might be undergoing home life stresses (my family had 2 deaths and another near-death this year, and it was not excellent for my productivity), or perhaps they are not completely motivated for their job. In the case of the latter, couldn't one argue that it's actually the manager's responsibility? Real world examples with anecdotes or statistics - rather than a somewhat clumsy metaphor for heroin addiction- would have made the argument more convincing.