# Why is Error Vector Magnitude (EVM) measured as an RMS value?

I do understand Voltage/Current measurement of a Sine Wave is in RMS, as average yields a zero, and RMS gives a true 'DC equivalent' value. But I do not understand why an EVM measurement could be in RMS, and not simply Average.

Is it because, similar to a sine wave, as symbols are mirrored in the IQ constellation plane, their individual EVM values when averaged yield a zero as well?