We wanted one number that reflected what the true cost is. We looked at $95m a year, we looked at a per user number and so on. In the end we rounded it all up and looked at Covec's most conservative estimate across the period in question.
As for the phrasing around it being a tax - I don't have a problem with using that term. A tax is "a cost the government imposes on you to pay to another person" and that's what's going on here. Sure, it's not using the IRD but that doesn't mean it's not a govt imposed cost transferring money from customers to Chorus.
I hear what you're saying though and comms around such matters is always a matter of fine judgements...