Boredom refers to the absence of want. This absence of want is why it's sometimes culturally correct to frown upon idleness. For many, volitional pressure is the most effective cause of want although this doesn't apply to all, like Russell pointed out in his essay In Praise of Idleness.
The absence of want makes people engage in activity they don't really want to do. This corrupts them by hindering their skill of evaluation. People whose wants have been suppressed by boredom are more likely to be unable to tell genuine motivation from aversion of punishment. The corruption caused by boredom explains why people stick to harmful or degenerate routines so that they mindlessly obey rules instead of taking time to figure out whether a given rule applies to the situation at hand. This is why sane people are sometimes committed to involuntary psychiatric treatment.