Great point. The reason for this is because we have no way of knowing
how to apply an attribution model from outside of the calculated metric
builder. For example, if you had revenue / orders and you applied
"Linear" to it - does that mean (linear revenue) / (linear orders) or
(linear revenue) / orders or revenue / (linear orders). Adding more
metrics, segments, calculations, etc. makes it hard for us to know how
to apply the model. Does this make sense?