High school dropout rates are seen as a problem by structural functionalists because they disrupt this system. Dropouts are less likely to have the skills and knowledge they need to get a good job, which means they are more likely to be unemployed or underemployed. They are also more likely to be involved in crime and other antisocial behavior. This can lead to a number of problems for society, such as increased poverty and social inequality, as well as decreased civic participation.
In addition, high school dropout rates can have a negative impact on the economy. Dropouts are less likely to earn as much money as those who graduate from high school, which means that they pay less in taxes and contribute less to the overall economy. This can lead to a number of problems, such as decreased economic growth, increased government debt, and cuts to public services.
For these reasons, structural functionalists are concerned about high school dropout rates and see them as a problem that needs to be addressed.