There is a ton of information in circuits that cannot be tagged. Wires should contain all information contained within the circuit.
My particular application: I have a shared project parameter in my circuits called "Breaker_function". I use this to indicate whether a breaker is to be GFCI, AFCI, Lockable, etc...
My company also wants to put this information in the circuit tag so it's clear in plan view. For example, if circuit P-3 needed a GFCI breaker, the tag would say P-3(G). To do this, I can add the project parameter to the wire and it's available for tagging, but it doesn't get its value from the circuit - therefore, I have to enter the parameter value twice: once for the circuit and once for the wire.
Why not make anything parameter/data contained within the circuit available in the wire also, so that it may be tagged?