In Alaska where I just left all "fixed" appliances are now required to have a means of disconnect as per 422.31(b).
This means that dishwashers, garbage disposals, waterheaters, range tops, wine coolers, built-in fridges, wall ovens, and any other fixed in place appliance that you can think of has to have a disconnect within sight. This can be a disconnect, a switch, or a cord and plug.
While I am not famliar with the local N.C. code this would seem to be an attempt to comply with the above referenced code article. You should consult your local AHJ (Authority Having Jurisdiction...your city, county, or state inspectors that have authority there and see if another means of disconnect is adequate. In order to comply with this most dishwashers nowadays are "plugged-in".
I think perhaps what the installers/electricians/whomever it is doing the install were trying to tell you is not that you would have a wall mounted switch that shuts off the dishwasher alongside the light and disposal switch. But rather that they needed to install a switch inside the cabinet where the dishwashers feed originates from. An alternative is for them to install a receptacle at the outlet and a cord on the dishwasher. As long as the cord length/wiresize is kept within the code limits.
Whoever qouted this code rule is correct but don't forget that there are several ways of complying with it. Since this is new construction you must comply with the "new" code as upheld in your area.
