Customer Citizen

Should the government of Washington D.C. view its residents as citizens or as customers? Or as customer citizens?

Now that I'm trying to register my car in DC, the DC department of motor vehicles seems to think that I am a customer. Their website for vehicle registration states the following advisory (emphasis added):

The best times to visit the [inspection] station are Tuesday, Wednesday or Thursday afternoons from 3 pm - 6 pm. Customers are advised that the days before and after a holiday and most Saturdays are especially busy due to many customers being off from work.