Why aren't we able to multiply or "mask" vectors ?

I would like to do this:

Vector3 testVector = new Vector3(10.0f, 10.0f, 10.0f);
Vector3 maskVector = new Vector3(1.0f, 0.0f, 0.0f);
Vector3 result = testVector * maskVector; 
result =* anotherstuff

instead of:

Vector3 testVector = new Vector3(10.0f, 10.0f, 10.0f);
Vector3 result = testVector;
testVector.y = 0.0f;
testVector.z = 0.0f;
result =* anotherstuff

Since I've heard it is more efficient for the processor to process consecutive vector intrinsic functions instead of having to come back and forth calculating floats ...

Is there a place where we can ask for features ?