Yeah, a lot of worker/management conflict is result of some combination of prioritizing power over efficiency (overworked workers don't have time to complain/organize), and plain old bad management. Things like long working hours reduce output, and as you say having sick people come in is also stupid.

So smart companies won't e.g. overwork their employees. But some of the conflicts are inherent in the relationship, e.g. how much money goes to workers.