If this is the case, your hiring and evaluating process has a deficiency, which should be an easy fix. However, assuming a decent hiring process, people genera

If this is the case, your hiring and evaluating process has a deficiency, which should be an easy fix. However, assuming a decent hiring process, people generally aren't rude from the get-go. The bigger question the study doesn't even tackle is how does rudeness evolve over time, and - again assuming rudeness isn't some intrinsic attribute - what factors lead to an increase in rudeness. If somebody is truly incompetent, sure, fire them. But incompetence is rarely so cut and dried, and points to a failure to invest in a person's or team's abilities. I don't think it's a stretch to see the proliferation of incompetence as a management failure in any case. If percieved incompetence leads to a lack of respect and therefore rudeness, it should come as no surprise why leaders who allowed such an environment to be created would be unable/unwilling to assess it accurately.