That is absolutely not true. See here:
http://wpilib.screenstepslive.com/s/...-robot-program. The example is in Java but the equivalent C++ will work From your example:
Code:
SmartDashboard::PutNumber("Pot Angle", angle);
That will show up on the SmartDashboard as a number, and you can change it to other types of displays such as a graph over time and other widgets, as seen here:
http://wpilib.screenstepslive.com/s/...anual-id=26401.