Route between Franklin and Brevard NC

I'm planning a trip to Franklin then to Brevard, NC in a 26' class A.

RV Parky app shows and provides a route north of US 64 between those two towns.  It doesn't even allow 64 to be selected as an option.

Might that be an inadvertent omission, or is there a good reason to avoid 64 in a motorhome?